/*
 * Copyright (c) 1999, 2006, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.comp;

import static com.sun.tools.javac.code.Flags.ABSTRACT;
import static com.sun.tools.javac.code.Flags.ANNOTATION;
import static com.sun.tools.javac.code.Flags.BLOCK;
import static com.sun.tools.javac.code.Flags.COMPOUND;
import static com.sun.tools.javac.code.Flags.DEPRECATED;
import static com.sun.tools.javac.code.Flags.ENUM;
import static com.sun.tools.javac.code.Flags.FINAL;
import static com.sun.tools.javac.code.Flags.GENERATEDCONSTR;
import static com.sun.tools.javac.code.Flags.HASINIT;
import static com.sun.tools.javac.code.Flags.INTERFACE;
import static com.sun.tools.javac.code.Flags.NATIVE;
import static com.sun.tools.javac.code.Flags.NOOUTERTHIS;
import static com.sun.tools.javac.code.Flags.PROPRIETARY;
import static com.sun.tools.javac.code.Flags.PUBLIC;
import static com.sun.tools.javac.code.Flags.STATIC;
import static com.sun.tools.javac.code.Flags.UNATTRIBUTED;
import static com.sun.tools.javac.code.Flags.VARARGS;
import static com.sun.tools.javac.code.Kinds.AMBIGUOUS;
import static com.sun.tools.javac.code.Kinds.ERR;
import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
import static com.sun.tools.javac.code.Kinds.MTH;
import static com.sun.tools.javac.code.Kinds.NIL;
import static com.sun.tools.javac.code.Kinds.PCK;
import static com.sun.tools.javac.code.Kinds.TYP;
import static com.sun.tools.javac.code.Kinds.VAL;
import static com.sun.tools.javac.code.Kinds.VAR;
import static com.sun.tools.javac.code.TypeTags.ARRAY;
import static com.sun.tools.javac.code.TypeTags.BYTE;
import static com.sun.tools.javac.code.TypeTags.CLASS;
import static com.sun.tools.javac.code.TypeTags.ERROR;
import static com.sun.tools.javac.code.TypeTags.FORALL;
import static com.sun.tools.javac.code.TypeTags.INT;
import static com.sun.tools.javac.code.TypeTags.METHOD;
import static com.sun.tools.javac.code.TypeTags.PACKAGE;
import static com.sun.tools.javac.code.TypeTags.TYPEVAR;
import static com.sun.tools.javac.code.TypeTags.VOID;
import static com.sun.tools.javac.code.TypeTags.WILDCARD;

import java.util.HashSet;
import java.util.Set;

import javax.lang.model.element.ElementKind;
import javax.tools.JavaFileObject;

import android.annotation.SuppressLint;

import com.sun.source.tree.IdentifierTree;
import com.sun.source.tree.MemberSelectTree;
import com.sun.source.tree.TreeVisitor;
import com.sun.source.util.SimpleTreeVisitor;
import com.sun.tools.javac.code.BoundKind;
import com.sun.tools.javac.code.Flags;
import com.sun.tools.javac.code.Kinds;
import com.sun.tools.javac.code.Lint;
import com.sun.tools.javac.code.Scope;
import com.sun.tools.javac.code.Source;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Symbol.ClassSymbol;
import com.sun.tools.javac.code.Symbol.CompletionFailure;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.code.Symbol.OperatorSymbol;
import com.sun.tools.javac.code.Symbol.PackageSymbol;
import com.sun.tools.javac.code.Symbol.TypeSymbol;
import com.sun.tools.javac.code.Symbol.VarSymbol;
import com.sun.tools.javac.code.Symtab;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Type.ArrayType;
import com.sun.tools.javac.code.Type.ClassType;
import com.sun.tools.javac.code.Type.ErrorType;
import com.sun.tools.javac.code.Type.ForAll;
import com.sun.tools.javac.code.Type.MethodType;
import com.sun.tools.javac.code.Type.TypeVar;
import com.sun.tools.javac.code.Type.WildcardType;
import com.sun.tools.javac.code.TypeTags;
import com.sun.tools.javac.code.Types;
import com.sun.tools.javac.jvm.ByteCodes;
import com.sun.tools.javac.jvm.Target;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.tree.JCTree.JCAnnotation;
import com.sun.tools.javac.tree.JCTree.JCArrayAccess;
import com.sun.tools.javac.tree.JCTree.JCArrayTypeTree;
import com.sun.tools.javac.tree.JCTree.JCAssert;
import com.sun.tools.javac.tree.JCTree.JCAssign;
import com.sun.tools.javac.tree.JCTree.JCAssignOp;
import com.sun.tools.javac.tree.JCTree.JCBinary;
import com.sun.tools.javac.tree.JCTree.JCBlock;
import com.sun.tools.javac.tree.JCTree.JCBreak;
import com.sun.tools.javac.tree.JCTree.JCCase;
import com.sun.tools.javac.tree.JCTree.JCCatch;
import com.sun.tools.javac.tree.JCTree.JCClassDecl;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.tree.JCTree.JCConditional;
import com.sun.tools.javac.tree.JCTree.JCContinue;
import com.sun.tools.javac.tree.JCTree.JCDoWhileLoop;
import com.sun.tools.javac.tree.JCTree.JCEnhancedForLoop;
import com.sun.tools.javac.tree.JCTree.JCErroneous;
import com.sun.tools.javac.tree.JCTree.JCExpression;
import com.sun.tools.javac.tree.JCTree.JCExpressionStatement;
import com.sun.tools.javac.tree.JCTree.JCFieldAccess;
import com.sun.tools.javac.tree.JCTree.JCForLoop;
import com.sun.tools.javac.tree.JCTree.JCIdent;
import com.sun.tools.javac.tree.JCTree.JCIf;
import com.sun.tools.javac.tree.JCTree.JCImport;
import com.sun.tools.javac.tree.JCTree.JCInstanceOf;
import com.sun.tools.javac.tree.JCTree.JCLabeledStatement;
import com.sun.tools.javac.tree.JCTree.JCLiteral;
import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
import com.sun.tools.javac.tree.JCTree.JCMethodInvocation;
import com.sun.tools.javac.tree.JCTree.JCNewArray;
import com.sun.tools.javac.tree.JCTree.JCNewClass;
import com.sun.tools.javac.tree.JCTree.JCParens;
import com.sun.tools.javac.tree.JCTree.JCPrimitiveTypeTree;
import com.sun.tools.javac.tree.JCTree.JCReturn;
import com.sun.tools.javac.tree.JCTree.JCSkip;
import com.sun.tools.javac.tree.JCTree.JCStatement;
import com.sun.tools.javac.tree.JCTree.JCSwitch;
import com.sun.tools.javac.tree.JCTree.JCSynchronized;
import com.sun.tools.javac.tree.JCTree.JCThrow;
import com.sun.tools.javac.tree.JCTree.JCTry;
import com.sun.tools.javac.tree.JCTree.JCTypeApply;
import com.sun.tools.javac.tree.JCTree.JCTypeCast;
import com.sun.tools.javac.tree.JCTree.JCTypeParameter;
import com.sun.tools.javac.tree.JCTree.JCUnary;
import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
import com.sun.tools.javac.tree.JCTree.JCWhileLoop;
import com.sun.tools.javac.tree.JCTree.JCWildcard;
import com.sun.tools.javac.tree.TreeInfo;
import com.sun.tools.javac.tree.TreeMaker;
import com.sun.tools.javac.util.Context;
import com.sun.tools.javac.util.JCDiagnostic;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.util.ListBuffer;
import com.sun.tools.javac.util.Log;
import com.sun.tools.javac.util.Name;
import com.sun.tools.javac.util.Options;
import com.sun.tools.javac.util.Position;
import com.sun.tools.javac.util.Warner;

/**
 * This is the main context-dependent analysis phase in GJC. It encompasses name
 * resolution, type checking and constant folding as subtasks. Some subtasks
 * involve auxiliary classes.
 * 
 * @see Check
 * @see Resolve
 * @see ConstFold
 * @see Infer
 * 
 *      <p>
 *      <b>This is NOT part of any supported API. If you write code that depends
 *      on this, you do so at your own risk. This code and its internal
 *      interfaces are subject to change or deletion without notice.</b>
 */
@SuppressLint("Assert")
public class Attr extends JCTree.Visitor {
	protected static final Context.Key<Attr> attrKey = new Context.Key<Attr>();

	final Name.Table names;
	final Log log;
	final Symtab syms;
	final Resolve rs;
	final Check chk;
	final MemberEnter memberEnter;
	final TreeMaker make;
	final ConstFold cfolder;
	final Enter enter;
	final Target target;
	final Types types;
	final Annotate annotate;

	public static Attr instance(Context context) {
		Attr instance = context.get(attrKey);
		if (instance == null)
			instance = new Attr(context);
		return instance;
	}

	protected Attr(Context context) {
		context.put(attrKey, this);

		names = Name.Table.instance(context);
		log = Log.instance(context);
		syms = Symtab.instance(context);
		rs = Resolve.instance(context);
		chk = Check.instance(context);
		memberEnter = MemberEnter.instance(context);
		make = TreeMaker.instance(context);
		enter = Enter.instance(context);
		cfolder = ConstFold.instance(context);
		target = Target.instance(context);
		types = Types.instance(context);
		annotate = Annotate.instance(context);

		Options options = Options.instance(context);

		Source source = Source.instance(context);
		allowGenerics = source.allowGenerics();
		allowVarargs = source.allowVarargs();
		allowEnums = source.allowEnums();
		allowBoxing = source.allowBoxing();
		allowCovariantReturns = source.allowCovariantReturns();
		allowAnonOuterThis = source.allowAnonOuterThis();
		relax = (options.get("-retrofit") != null || options.get("-relax") != null);
		useBeforeDeclarationWarning = options
				.get("useBeforeDeclarationWarning") != null;
	}

	/**
	 * Switch: relax some constraints for retrofit mode.
	 */
	boolean relax;

	/**
	 * Switch: support generics?
	 */
	boolean allowGenerics;

	/**
	 * Switch: allow variable-arity methods.
	 */
	boolean allowVarargs;

	/**
	 * Switch: support enums?
	 */
	boolean allowEnums;

	/**
	 * Switch: support boxing and unboxing?
	 */
	boolean allowBoxing;

	/**
	 * Switch: support covariant result types?
	 */
	boolean allowCovariantReturns;

	/**
	 * Switch: allow references to surrounding object from anonymous objects
	 * during constructor call?
	 */
	boolean allowAnonOuterThis;

	/**
	 * Switch: warn about use of variable before declaration? RFE: 6425594
	 */
	boolean useBeforeDeclarationWarning;

	/**
	 * Check kind and type of given tree against protokind and prototype. If
	 * check succeeds, store type in tree and return it. If check fails, store
	 * errType in tree and return it. No checks are performed if the prototype
	 * is a method type. Its not necessary in this case since we know that kind
	 * and type are correct.
	 * 
	 * @param tree
	 *            The tree whose kind and type is checked
	 * @param owntype
	 *            The computed type of the tree
	 * @param ownkind
	 *            The computed kind of the tree
	 * @param pkind
	 *            The expected kind (or: protokind) of the tree
	 * @param pt
	 *            The expected type (or: prototype) of the tree
	 */
	Type check(JCTree tree, Type owntype, int ownkind, int pkind, Type pt) {
		if (owntype.tag != ERROR && pt.tag != METHOD && pt.tag != FORALL) {
			if ((ownkind & ~pkind) == 0) {
				owntype = chk.checkType(tree.pos(), owntype, pt);
			} else {
				log.error(tree.pos(), "unexpected.type",
						Resolve.kindNames(pkind), Resolve.kindName(ownkind));
				owntype = syms.errType;
			}
		}
		tree.type = owntype;
		return owntype;
	}

	/**
	 * Is given blank final variable assignable, i.e. in a scope where it may be
	 * assigned to even though it is final?
	 * 
	 * @param v
	 *            The blank final variable.
	 * @param env
	 *            The current environment.
	 */
	boolean isAssignableAsBlankFinal(VarSymbol v, Env<AttrContext> env) {
		Symbol owner = env.info.scope.owner;
		// owner refers to the innermost variable, method or
		// initializer block declaration at this point.
		return v.owner == owner
				|| ((owner.name == names.init || // i.e. we are in a constructor
						owner.kind == VAR || // i.e. we are in a variable
												// initializer
						(owner.flags() & BLOCK) != 0) // i.e. we are in an
														// initializer block
						&& v.owner == owner.owner && ((v.flags() & STATIC) != 0) == Resolve
						.isStatic(env));
	}

	/**
	 * Check that variable can be assigned to.
	 * 
	 * @param pos
	 *            The current source code position.
	 * @param v
	 *            The assigned varaible
	 * @param base
	 *            If the variable is referred to in a Select, the part to the
	 *            left of the `.', null otherwise.
	 * @param env
	 *            The current environment.
	 */
	void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base,
			Env<AttrContext> env) {
		if ((v.flags() & FINAL) != 0
				&& ((v.flags() & HASINIT) != 0 || !((base == null || (base
						.getTag() == JCTree.IDENT && TreeInfo.name(base) == names._this)) && isAssignableAsBlankFinal(
						v, env)))) {
			log.error(pos, "cant.assign.val.to.final.var", v);
		}
	}

	/**
	 * Does tree represent a static reference to an identifier? It is assumed
	 * that tree is either a SELECT or an IDENT. We have to weed out selects
	 * from non-type names here.
	 * 
	 * @param tree
	 *            The candidate tree.
	 */
	boolean isStaticReference(JCTree tree) {
		if (tree.getTag() == JCTree.SELECT) {
			Symbol lsym = TreeInfo.symbol(((JCFieldAccess) tree).selected);
			if (lsym == null || lsym.kind != TYP) {
				return false;
			}
		}
		return true;
	}

	/**
	 * Is this symbol a type?
	 */
	static boolean isType(Symbol sym) {
		return sym != null && sym.kind == TYP;
	}

	/**
	 * The current `this' symbol.
	 * 
	 * @param env
	 *            The current environment.
	 */
	Symbol thisSym(DiagnosticPosition pos, Env<AttrContext> env) {
		return rs.resolveSelf(pos, env, env.enclClass.sym, names._this);
	}

	/**
	 * Attribute a parsed identifier.
	 * 
	 * @param tree
	 *            Parsed identifier name
	 * @param topLevel
	 *            The toplevel to use
	 */
	public Symbol attribIdent(JCTree tree, JCCompilationUnit topLevel) {
		Env<AttrContext> localEnv = enter.topLevelEnv(topLevel);
		localEnv.enclClass = make.ClassDef(make.Modifiers(0),
				syms.errSymbol.name, null, null, null, null);
		localEnv.enclClass.sym = syms.errSymbol;
		return tree.accept(identAttributer, localEnv);
	}

	// where
	private TreeVisitor<Symbol, Env<AttrContext>> identAttributer = new IdentAttributer();

	private class IdentAttributer extends
			SimpleTreeVisitor<Symbol, Env<AttrContext>> {
		@Override
		public Symbol visitMemberSelect(MemberSelectTree node,
				Env<AttrContext> env) {
			Symbol site = visit(node.getExpression(), env);
			if (site.kind == ERR)
				return site;
			Name name = (Name) node.getIdentifier();
			if (site.kind == PCK) {
				env.toplevel.packge = (PackageSymbol) site;
				return rs.findIdentInPackage(env, (TypeSymbol) site, name, TYP
						| PCK);
			} else {
				env.enclClass.sym = (ClassSymbol) site;
				return rs.findMemberType(env, site.asType(), name,
						(TypeSymbol) site);
			}
		}

		@Override
		public Symbol visitIdentifier(IdentifierTree node, Env<AttrContext> env) {
			return rs.findIdent(env, (Name) node.getName(), TYP | PCK);
		}
	}

	public Type coerce(Type etype, Type ttype) {
		return cfolder.coerce(etype, ttype);
	}

	public Type attribType(JCTree node, TypeSymbol sym) {
		Env<AttrContext> env = enter.typeEnvs.get(sym);
		Env<AttrContext> localEnv = env.dup(node, env.info.dup());
		return attribTree(node, localEnv, Kinds.TYP, Type.noType);
	}

	public Env<AttrContext> attribExprToTree(JCTree expr, Env<AttrContext> env,
			JCTree tree) {
		breakTree = tree;
		JavaFileObject prev = log.useSource(null);
		try {
			attribExpr(expr, env);
		} catch (BreakAttr b) {
			return b.env;
		} finally {
			breakTree = null;
			log.useSource(prev);
		}
		return env;
	}

	public Env<AttrContext> attribStatToTree(JCTree stmt, Env<AttrContext> env,
			JCTree tree) {
		breakTree = tree;
		JavaFileObject prev = log.useSource(null);
		try {
			attribStat(stmt, env);
		} catch (BreakAttr b) {
			return b.env;
		} finally {
			breakTree = null;
			log.useSource(prev);
		}
		return env;
	}

	private JCTree breakTree = null;

	private static class BreakAttr extends RuntimeException {
		static final long serialVersionUID = -6924771130405446405L;
		private Env<AttrContext> env;

		private BreakAttr(Env<AttrContext> env) {
			this.env = env;
		}
	}

	/* ************************************************************************
	 * Visitor methods
	 * ***********************************************************************
	 */

	/**
	 * Visitor argument: the current environment.
	 */
	Env<AttrContext> env;

	/**
	 * Visitor argument: the currently expected proto-kind.
	 */
	int pkind;

	/**
	 * Visitor argument: the currently expected proto-type.
	 */
	Type pt;

	/**
	 * Visitor result: the computed type.
	 */
	Type result;

	/**
	 * Visitor method: attribute a tree, catching any completion failure
	 * exceptions. Return the tree's type.
	 * 
	 * @param tree
	 *            The tree to be visited.
	 * @param env
	 *            The environment visitor argument.
	 * @param pkind
	 *            The protokind visitor argument.
	 * @param pt
	 *            The prototype visitor argument.
	 */
	Type attribTree(JCTree tree, Env<AttrContext> env, int pkind, Type pt) {
		Env<AttrContext> prevEnv = this.env;
		int prevPkind = this.pkind;
		Type prevPt = this.pt;
		try {
			this.env = env;
			this.pkind = pkind;
			this.pt = pt;
			tree.accept(this);
			if (tree == breakTree)
				throw new BreakAttr(env);
			return result;
		} catch (CompletionFailure ex) {
			tree.type = syms.errType;
			return chk.completionError(tree.pos(), ex);
		} finally {
			this.env = prevEnv;
			this.pkind = prevPkind;
			this.pt = prevPt;
		}
	}

	/**
	 * Derived visitor method: attribute an expression tree.
	 */
	public Type attribExpr(JCTree tree, Env<AttrContext> env, Type pt) {
		return attribTree(tree, env, VAL, pt.tag != ERROR ? pt : Type.noType);
	}

	/**
	 * Derived visitor method: attribute an expression tree with no constraints
	 * on the computed type.
	 */
	Type attribExpr(JCTree tree, Env<AttrContext> env) {
		return attribTree(tree, env, VAL, Type.noType);
	}

	/**
	 * Derived visitor method: attribute a type tree.
	 */
	Type attribType(JCTree tree, Env<AttrContext> env) {
		Type result = attribTree(tree, env, TYP, Type.noType);
		return result;
	}

	/**
	 * Derived visitor method: attribute a statement or definition tree.
	 */
	public Type attribStat(JCTree tree, Env<AttrContext> env) {
		return attribTree(tree, env, NIL, Type.noType);
	}

	/**
	 * Attribute a list of expressions, returning a list of types.
	 */
	List<Type> attribExprs(List<JCExpression> trees, Env<AttrContext> env,
			Type pt) {
		ListBuffer<Type> ts = new ListBuffer<Type>();
		for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
			ts.append(attribExpr(l.head, env, pt));
		return ts.toList();
	}

	/**
	 * Attribute a list of statements, returning nothing.
	 */
	<T extends JCTree> void attribStats(List<T> trees, Env<AttrContext> env) {
		for (List<T> l = trees; l.nonEmpty(); l = l.tail)
			attribStat(l.head, env);
	}

	/**
	 * Attribute the arguments in a method call, returning a list of types.
	 */
	List<Type> attribArgs(List<JCExpression> trees, Env<AttrContext> env) {
		ListBuffer<Type> argtypes = new ListBuffer<Type>();
		for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
			argtypes.append(chk.checkNonVoid(l.head.pos(), types
					.upperBound(attribTree(l.head, env, VAL, Infer.anyPoly))));
		return argtypes.toList();
	}

	/**
	 * Attribute a type argument list, returning a list of types.
	 */
	List<Type> attribTypes(List<JCExpression> trees, Env<AttrContext> env) {
		ListBuffer<Type> argtypes = new ListBuffer<Type>();
		for (List<JCExpression> l = trees; l.nonEmpty(); l = l.tail)
			argtypes.append(chk.checkRefType(l.head.pos(),
					attribType(l.head, env)));
		return argtypes.toList();
	}

	/**
	 * Attribute type variables (of generic classes or methods). Compound types
	 * are attributed later in attribBounds.
	 * 
	 * @param typarams
	 *            the type variables to enter
	 * @param env
	 *            the current environment
	 */
	void attribTypeVariables(List<JCTypeParameter> typarams,
			Env<AttrContext> env) {
		for (JCTypeParameter tvar : typarams) {
			TypeVar a = (TypeVar) tvar.type;
			if (!tvar.bounds.isEmpty()) {
				List<Type> bounds = List.of(attribType(tvar.bounds.head, env));
				for (JCExpression bound : tvar.bounds.tail)
					bounds = bounds.prepend(attribType(bound, env));
				types.setBounds(a, bounds.reverse());
			} else {
				// if no bounds are given, assume a single bound of
				// java.lang.Object.
				types.setBounds(a, List.of(syms.objectType));
			}
		}
		for (JCTypeParameter tvar : typarams)
			chk.checkNonCyclic(tvar.pos(), (TypeVar) tvar.type);
		attribStats(typarams, env);
	}

	void attribBounds(List<JCTypeParameter> typarams) {
		for (JCTypeParameter typaram : typarams) {
			Type bound = typaram.type.getUpperBound();
			if (bound != null && bound.tsym instanceof ClassSymbol) {
				ClassSymbol c = (ClassSymbol) bound.tsym;
				if ((c.flags_field & COMPOUND) != 0) {
					assert (c.flags_field & UNATTRIBUTED) != 0 : c;
					attribClass(typaram.pos(), c);
				}
			}
		}
	}

	/**
	 * Attribute the type references in a list of annotations.
	 */
	void attribAnnotationTypes(List<JCAnnotation> annotations,
			Env<AttrContext> env) {
		for (List<JCAnnotation> al = annotations; al.nonEmpty(); al = al.tail) {
			JCAnnotation a = al.head;
			attribType(a.annotationType, env);
		}
	}

	/**
	 * Attribute type reference in an `extends' or `implements' clause.
	 * 
	 * @param tree
	 *            The tree making up the type reference.
	 * @param env
	 *            The environment current at the reference.
	 * @param classExpected
	 *            true if only a class is expected here.
	 * @param interfaceExpected
	 *            true if only an interface is expected here.
	 */
	Type attribBase(JCTree tree, Env<AttrContext> env, boolean classExpected,
			boolean interfaceExpected, boolean checkExtensible) {
		Type t = attribType(tree, env);
		return checkBase(t, tree, env, classExpected, interfaceExpected,
				checkExtensible);
	}

	Type checkBase(Type t, JCTree tree, Env<AttrContext> env,
			boolean classExpected, boolean interfaceExpected,
			boolean checkExtensible) {
		if (t.tag == TYPEVAR && !classExpected && !interfaceExpected) {
			// check that type variable is already visible
			if (t.getUpperBound() == null) {
				log.error(tree.pos(), "illegal.forward.ref");
				return syms.errType;
			}
		} else {
			t = chk.checkClassType(tree.pos(), t, checkExtensible
					| !allowGenerics);
		}
		if (interfaceExpected && (t.tsym.flags() & INTERFACE) == 0) {
			log.error(tree.pos(), "intf.expected.here");
			// return errType is necessary since otherwise there might
			// be undetected cycles which cause attribution to loop
			return syms.errType;
		} else if (checkExtensible && classExpected
				&& (t.tsym.flags() & INTERFACE) != 0) {
			log.error(tree.pos(), "no.intf.expected.here");
			return syms.errType;
		}
		if (checkExtensible && ((t.tsym.flags() & FINAL) != 0)) {
			log.error(tree.pos(), "cant.inherit.from.final", t.tsym);
		}
		chk.checkNonCyclic(tree.pos(), t);
		return t;
	}

	public void visitClassDef(JCClassDecl tree) {
		// Local classes have not been entered yet, so we need to do it now:
		if ((env.info.scope.owner.kind & (VAR | MTH)) != 0)
			enter.classEnter(tree, env);

		ClassSymbol c = tree.sym;
		if (c == null) {
			// exit in case something drastic went wrong during enter.
			result = null;
		} else {
			// make sure class has been completed:
			c.complete();

			// If this class appears as an anonymous class
			// in a superclass constructor call where
			// no explicit outer instance is given,
			// disable implicit outer instance from being passed.
			// (This would be an illegal access to "this before super").
			if (env.info.isSelfCall && env.tree.getTag() == JCTree.NEWCLASS
					&& ((JCNewClass) env.tree).encl == null) {
				c.flags_field |= NOOUTERTHIS;
			}
			attribClass(tree.pos(), c);
			result = tree.type = c.type;
		}
	}

	public void visitMethodDef(JCMethodDecl tree) {
		MethodSymbol m = tree.sym;

		Lint lint = env.info.lint.augment(m.attributes_field, m.flags());
		Lint prevLint = chk.setLint(lint);
		try {
			chk.checkDeprecatedAnnotation(tree.pos(), m);

			attribBounds(tree.typarams);

			// If we override any other methods, check that we do so properly.
			// JLS ???
			chk.checkOverride(tree, m);

			// Create a new environment with local scope
			// for attributing the method.
			Env<AttrContext> localEnv = memberEnter.methodEnv(tree, env);

			localEnv.info.lint = lint;

			// Enter all type parameters into the local method scope.
			for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
				localEnv.info.scope.enterIfAbsent(l.head.type.tsym);

			ClassSymbol owner = env.enclClass.sym;
			if ((owner.flags() & ANNOTATION) != 0 && tree.params.nonEmpty())
				log.error(tree.params.head.pos(),
						"intf.annotation.members.cant.have.params");

			// Attribute all value parameters.
			for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
				attribStat(l.head, localEnv);
			}

			// Check that type parameters are well-formed.
			chk.validateTypeParams(tree.typarams);
			if ((owner.flags() & ANNOTATION) != 0 && tree.typarams.nonEmpty())
				log.error(tree.typarams.head.pos(),
						"intf.annotation.members.cant.have.type.params");

			// Check that result type is well-formed.
			chk.validate(tree.restype);
			if ((owner.flags() & ANNOTATION) != 0)
				chk.validateAnnotationType(tree.restype);

			if ((owner.flags() & ANNOTATION) != 0)
				chk.validateAnnotationMethod(tree.pos(), m);

			// Check that all exceptions mentioned in the throws clause extend
			// java.lang.Throwable.
			if ((owner.flags() & ANNOTATION) != 0 && tree.thrown.nonEmpty())
				log.error(tree.thrown.head.pos(),
						"throws.not.allowed.in.intf.annotation");
			for (List<JCExpression> l = tree.thrown; l.nonEmpty(); l = l.tail)
				chk.checkType(l.head.pos(), l.head.type, syms.throwableType);

			if (tree.body == null) {
				// Empty bodies are only allowed for
				// abstract, native, or interface methods, or for methods
				// in a retrofit signature class.
				if ((owner.flags() & INTERFACE) == 0
						&& (tree.mods.flags & (ABSTRACT | NATIVE)) == 0
						&& !relax)
					log.error(tree.pos(), "missing.meth.body.or.decl.abstract");
				if (tree.defaultValue != null) {
					if ((owner.flags() & ANNOTATION) == 0)
						log.error(tree.pos(),
								"default.allowed.in.intf.annotation.member");
				}
			} else if ((owner.flags() & INTERFACE) != 0) {
				log.error(tree.body.pos(), "intf.meth.cant.have.body");
			} else if ((tree.mods.flags & ABSTRACT) != 0) {
				log.error(tree.pos(), "abstract.meth.cant.have.body");
			} else if ((tree.mods.flags & NATIVE) != 0) {
				log.error(tree.pos(), "native.meth.cant.have.body");
			} else {
				// Add an implicit super() call unless an explicit call to
				// super(...) or this(...) is given
				// or we are compiling class java.lang.Object.
				if (tree.name == names.init && owner.type != syms.objectType) {
					JCBlock body = tree.body;
					if (body.stats.isEmpty()
							|| !TreeInfo.isSelfCall(body.stats.head)) {
						body.stats = body.stats.prepend(memberEnter.SuperCall(
								make.at(body.pos), List.<Type> nil(),
								List.<JCVariableDecl> nil(), false));
					} else if ((env.enclClass.sym.flags() & ENUM) != 0
							&& (tree.mods.flags & GENERATEDCONSTR) == 0
							&& TreeInfo.isSuperCall(body.stats.head)) {
						// enum constructors are not allowed to call super
						// directly, so make sure there aren't any super calls
						// in enum constructors, except in the compiler
						// generated one.
						log.error(tree.body.stats.head.pos(),
								"call.to.super.not.allowed.in.enum.ctor",
								env.enclClass.sym);
					}
				}

				// Attribute method body.
				attribStat(tree.body, localEnv);
			}
			localEnv.info.scope.leave();
			result = tree.type = m.type;
			chk.validateAnnotations(tree.mods.annotations, m);

		} finally {
			chk.setLint(prevLint);
		}
	}

	public void visitVarDef(JCVariableDecl tree) {
		// Local variables have not been entered yet, so we need to do it now:
		if (env.info.scope.owner.kind == MTH) {
			if (tree.sym != null) {
				// parameters have already been entered
				env.info.scope.enter(tree.sym);
			} else {
				memberEnter.memberEnter(tree, env);
				annotate.flush();
			}
		}

		// Check that the variable's declared type is well-formed.
		chk.validate(tree.vartype);

		VarSymbol v = tree.sym;
		Lint lint = env.info.lint.augment(v.attributes_field, v.flags());
		Lint prevLint = chk.setLint(lint);

		try {
			chk.checkDeprecatedAnnotation(tree.pos(), v);

			if (tree.init != null) {
				if ((v.flags_field & FINAL) != 0
						&& tree.init.getTag() != JCTree.NEWCLASS) {
					// In this case, `v' is final. Ensure that it's initializer
					// is
					// evaluated.
					v.getConstValue(); // ensure initializer is evaluated
				} else {
					// Attribute initializer in a new environment
					// with the declared variable as owner.
					// Check that initializer conforms to variable's declared
					// type.
					Env<AttrContext> initEnv = memberEnter.initEnv(tree, env);
					initEnv.info.lint = lint;
					// In order to catch self-references, we set the variable's
					// declaration position to maximal possible value,
					// effectively
					// marking the variable as undefined.
					v.pos = Position.MAXPOS;
					attribExpr(tree.init, initEnv, v.type);
					v.pos = tree.pos;
				}
			}
			result = tree.type = v.type;
			chk.validateAnnotations(tree.mods.annotations, v);
		} finally {
			chk.setLint(prevLint);
		}
	}

	public void visitSkip(JCSkip tree) {
		result = null;
	}

	public void visitBlock(JCBlock tree) {
		if (env.info.scope.owner.kind == TYP) {
			// Block is a static or instance initializer;
			// let the owner of the environment be a freshly
			// created BLOCK-method.
			Env<AttrContext> localEnv = env.dup(tree,
					env.info.dup(env.info.scope.dupUnshared()));
			localEnv.info.scope.owner = new MethodSymbol(tree.flags | BLOCK,
					names.empty, null, env.info.scope.owner);
			if ((tree.flags & STATIC) != 0)
				localEnv.info.staticLevel++;
			attribStats(tree.stats, localEnv);
		} else {
			// Create a new local environment with a local scope.
			Env<AttrContext> localEnv = env.dup(tree,
					env.info.dup(env.info.scope.dup()));
			attribStats(tree.stats, localEnv);
			localEnv.info.scope.leave();
		}
		result = null;
	}

	public void visitDoLoop(JCDoWhileLoop tree) {
		attribStat(tree.body, env.dup(tree));
		attribExpr(tree.cond, env, syms.booleanType);
		result = null;
	}

	public void visitWhileLoop(JCWhileLoop tree) {
		attribExpr(tree.cond, env, syms.booleanType);
		attribStat(tree.body, env.dup(tree));
		result = null;
	}

	public void visitForLoop(JCForLoop tree) {
		Env<AttrContext> loopEnv = env.dup(env.tree,
				env.info.dup(env.info.scope.dup()));
		attribStats(tree.init, loopEnv);
		if (tree.cond != null)
			attribExpr(tree.cond, loopEnv, syms.booleanType);
		loopEnv.tree = tree; // before, we were not in loop!
		attribStats(tree.step, loopEnv);
		attribStat(tree.body, loopEnv);
		loopEnv.info.scope.leave();
		result = null;
	}

	public void visitForeachLoop(JCEnhancedForLoop tree) {
		Env<AttrContext> loopEnv = env.dup(env.tree,
				env.info.dup(env.info.scope.dup()));
		attribStat(tree.var, loopEnv);
		Type exprType = types.upperBound(attribExpr(tree.expr, loopEnv));
		chk.checkNonVoid(tree.pos(), exprType);
		Type elemtype = types.elemtype(exprType); // perhaps expr is an array?
		if (elemtype == null) {
			// or perhaps expr implements Iterable<T>?
			Type base = types.asSuper(exprType, syms.iterableType.tsym);
			if (base == null) {
				log.error(tree.expr.pos(), "foreach.not.applicable.to.type");
				elemtype = syms.errType;
			} else {
				List<Type> iterableParams = base.allparams();
				elemtype = iterableParams.isEmpty() ? syms.objectType : types
						.upperBound(iterableParams.head);
			}
		}
		chk.checkType(tree.expr.pos(), elemtype, tree.var.sym.type);
		loopEnv.tree = tree; // before, we were not in loop!
		attribStat(tree.body, loopEnv);
		loopEnv.info.scope.leave();
		result = null;
	}

	public void visitLabelled(JCLabeledStatement tree) {
		// Check that label is not used in an enclosing statement
		Env<AttrContext> env1 = env;
		while (env1 != null && env1.tree.getTag() != JCTree.CLASSDEF) {
			if (env1.tree.getTag() == JCTree.LABELLED
					&& ((JCLabeledStatement) env1.tree).label == tree.label) {
				log.error(tree.pos(), "label.already.in.use", tree.label);
				break;
			}
			env1 = env1.next;
		}

		attribStat(tree.body, env.dup(tree));
		result = null;
	}

	public void visitSwitch(JCSwitch tree) {
		Type seltype = attribExpr(tree.selector, env);

		Env<AttrContext> switchEnv = env.dup(tree,
				env.info.dup(env.info.scope.dup()));

		boolean enumSwitch = allowEnums
				&& (seltype.tsym.flags() & Flags.ENUM) != 0;
		if (!enumSwitch)
			seltype = chk.checkType(tree.selector.pos(), seltype, syms.intType);

		// Attribute all cases and
		// check that there are no duplicate case labels or default clauses.
		Set<Object> labels = new HashSet<Object>(); // The set of case labels.
		boolean hasDefault = false; // Is there a default label?
		for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
			JCCase c = l.head;
			Env<AttrContext> caseEnv = switchEnv.dup(c,
					env.info.dup(switchEnv.info.scope.dup()));
			if (c.pat != null) {
				if (enumSwitch) {
					Symbol sym = enumConstant(c.pat, seltype);
					if (sym == null) {
						log.error(c.pat.pos(), "enum.const.req");
					} else if (!labels.add(sym)) {
						log.error(c.pos(), "duplicate.case.label");
					}
				} else {
					Type pattype = attribExpr(c.pat, switchEnv, seltype);
					if (pattype.tag != ERROR) {
						if (pattype.constValue() == null) {
							log.error(c.pat.pos(), "const.expr.req");
						} else if (labels.contains(pattype.constValue())) {
							log.error(c.pos(), "duplicate.case.label");
						} else {
							labels.add(pattype.constValue());
						}
					}
				}
			} else if (hasDefault) {
				log.error(c.pos(), "duplicate.default.label");
			} else {
				hasDefault = true;
			}
			attribStats(c.stats, caseEnv);
			caseEnv.info.scope.leave();
			addVars(c.stats, switchEnv.info.scope);
		}

		switchEnv.info.scope.leave();
		result = null;
	}

	// where
	/** Add any variables defined in stats to the switch scope. */
	private static void addVars(List<JCStatement> stats, Scope switchScope) {
		for (; stats.nonEmpty(); stats = stats.tail) {
			JCTree stat = stats.head;
			if (stat.getTag() == JCTree.VARDEF)
				switchScope.enter(((JCVariableDecl) stat).sym);
		}
	}

	// where
	/** Return the selected enumeration constant symbol, or null. */
	private Symbol enumConstant(JCTree tree, Type enumType) {
		if (tree.getTag() != JCTree.IDENT) {
			log.error(tree.pos(), "enum.label.must.be.unqualified.enum");
			return syms.errSymbol;
		}
		JCIdent ident = (JCIdent) tree;
		Name name = ident.name;
		for (Scope.Entry e = enumType.tsym.members().lookup(name); e.scope != null; e = e
				.next()) {
			if (e.sym.kind == VAR) {
				Symbol s = ident.sym = e.sym;
				((VarSymbol) s).getConstValue(); // ensure initializer is
													// evaluated
				ident.type = s.type;
				return ((s.flags_field & Flags.ENUM) == 0) ? null : s;
			}
		}
		return null;
	}

	public void visitSynchronized(JCSynchronized tree) {
		chk.checkRefType(tree.pos(), attribExpr(tree.lock, env));
		attribStat(tree.body, env);
		result = null;
	}

	public void visitTry(JCTry tree) {
		// Attribute body
		attribStat(tree.body, env.dup(tree, env.info.dup()));

		// Attribute catch clauses
		for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
			JCCatch c = l.head;
			Env<AttrContext> catchEnv = env.dup(c,
					env.info.dup(env.info.scope.dup()));
			Type ctype = attribStat(c.param, catchEnv);
			if (c.param.type.tsym.kind == Kinds.VAR) {
				c.param.sym.setData(ElementKind.EXCEPTION_PARAMETER);
			}
			chk.checkType(c.param.vartype.pos(),
					chk.checkClassType(c.param.vartype.pos(), ctype),
					syms.throwableType);
			attribStat(c.body, catchEnv);
			catchEnv.info.scope.leave();
		}

		// Attribute finalizer
		if (tree.finalizer != null)
			attribStat(tree.finalizer, env);
		result = null;
	}

	public void visitConditional(JCConditional tree) {
		attribExpr(tree.cond, env, syms.booleanType);
		attribExpr(tree.truepart, env);
		attribExpr(tree.falsepart, env);
		result = check(
				tree,
				capture(condType(tree.pos(), tree.cond.type,
						tree.truepart.type, tree.falsepart.type)), VAL, pkind,
				pt);
	}

	// where
	/**
	 * Compute the type of a conditional expression, after checking that it
	 * exists. See Spec 15.25.
	 * 
	 * @param pos
	 *            The source position to be used for error diagnostics.
	 * @param condtype
	 *            The type of the expression's condition.
	 * @param thentype
	 *            The type of the expression's then-part.
	 * @param elsetype
	 *            The type of the expression's else-part.
	 */
	private Type condType(DiagnosticPosition pos, Type condtype, Type thentype,
			Type elsetype) {
		Type ctype = condType1(pos, condtype, thentype, elsetype);

		// If condition and both arms are numeric constants,
		// evaluate at compile-time.
		return ((condtype.constValue() != null)
				&& (thentype.constValue() != null) && (elsetype.constValue() != null)) ? cfolder
				.coerce(condtype.isTrue() ? thentype : elsetype, ctype) : ctype;
	}

	/**
	 * Compute the type of a conditional expression, after checking that it
	 * exists. Does not take into account the special case where condition and
	 * both arms are constants.
	 * 
	 * @param pos
	 *            The source position to be used for error diagnostics.
	 * @param condtype
	 *            The type of the expression's condition.
	 * @param thentype
	 *            The type of the expression's then-part.
	 * @param elsetype
	 *            The type of the expression's else-part.
	 */
	private Type condType1(DiagnosticPosition pos, Type condtype,
			Type thentype, Type elsetype) {
		// If same type, that is the result
		if (types.isSameType(thentype, elsetype))
			return thentype.baseType();

		Type thenUnboxed = (!allowBoxing || thentype.isPrimitive()) ? thentype
				: types.unboxedType(thentype);
		Type elseUnboxed = (!allowBoxing || elsetype.isPrimitive()) ? elsetype
				: types.unboxedType(elsetype);

		// Otherwise, if both arms can be converted to a numeric
		// type, return the least numeric type that fits both arms
		// (i.e. return larger of the two, or return int if one
		// arm is short, the other is char).
		if (thenUnboxed.isPrimitive() && elseUnboxed.isPrimitive()) {
			// If one arm has an integer subrange type (i.e., byte,
			// short, or char), and the other is an integer constant
			// that fits into the subrange, return the subrange type.
			if (thenUnboxed.tag < INT && elseUnboxed.tag == INT
					&& types.isAssignable(elseUnboxed, thenUnboxed))
				return thenUnboxed.baseType();
			if (elseUnboxed.tag < INT && thenUnboxed.tag == INT
					&& types.isAssignable(thenUnboxed, elseUnboxed))
				return elseUnboxed.baseType();

			for (int i = BYTE; i < VOID; i++) {
				Type candidate = syms.typeOfTag[i];
				if (types.isSubtype(thenUnboxed, candidate)
						&& types.isSubtype(elseUnboxed, candidate))
					return candidate;
			}
		}

		// Those were all the cases that could result in a primitive
		if (allowBoxing) {
			if (thentype.isPrimitive())
				thentype = types.boxedClass(thentype).type;
			if (elsetype.isPrimitive())
				elsetype = types.boxedClass(elsetype).type;
		}

		if (types.isSubtype(thentype, elsetype))
			return elsetype.baseType();
		if (types.isSubtype(elsetype, thentype))
			return thentype.baseType();

		if (!allowBoxing || thentype.tag == VOID || elsetype.tag == VOID) {
			log.error(pos, "neither.conditional.subtype", thentype, elsetype);
			return thentype.baseType();
		}

		// both are known to be reference types. The result is
		// lub(thentype,elsetype). This cannot fail, as it will
		// always be possible to infer "Object" if nothing better.
		return types.lub(thentype.baseType(), elsetype.baseType());
	}

	public void visitIf(JCIf tree) {
		attribExpr(tree.cond, env, syms.booleanType);
		attribStat(tree.thenpart, env);
		if (tree.elsepart != null)
			attribStat(tree.elsepart, env);
		chk.checkEmptyIf(tree);
		result = null;
	}

	public void visitExec(JCExpressionStatement tree) {
		attribExpr(tree.expr, env);
		result = null;
	}

	public void visitBreak(JCBreak tree) {
		tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
		result = null;
	}

	public void visitContinue(JCContinue tree) {
		tree.target = findJumpTarget(tree.pos(), tree.getTag(), tree.label, env);
		result = null;
	}

	// where
	/**
	 * Return the target of a break or continue statement, if it exists, report
	 * an error if not. Note: The target of a labelled break or continue is the
	 * (non-labelled) statement tree referred to by the label, not the tree
	 * representing the labelled statement itself.
	 * 
	 * @param pos
	 *            The position to be used for error diagnostics
	 * @param tag
	 *            The tag of the jump statement. This is either Tree.BREAK or
	 *            Tree.CONTINUE.
	 * @param label
	 *            The label of the jump statement, or null if no label is given.
	 * @param env
	 *            The environment current at the jump statement.
	 */
	private JCTree findJumpTarget(DiagnosticPosition pos, int tag, Name label,
			Env<AttrContext> env) {
		// Search environments outwards from the point of jump.
		Env<AttrContext> env1 = env;
		LOOP: while (env1 != null) {
			switch (env1.tree.getTag()) {
			case JCTree.LABELLED:
				JCLabeledStatement labelled = (JCLabeledStatement) env1.tree;
				if (label == labelled.label) {
					// If jump is a continue, check that target is a loop.
					if (tag == JCTree.CONTINUE) {
						if (labelled.body.getTag() != JCTree.DOLOOP
								&& labelled.body.getTag() != JCTree.WHILELOOP
								&& labelled.body.getTag() != JCTree.FORLOOP
								&& labelled.body.getTag() != JCTree.FOREACHLOOP)
							log.error(pos, "not.loop.label", label);
						// Found labelled statement target, now go inwards
						// to next non-labelled tree.
						return TreeInfo.referencedStatement(labelled);
					} else {
						return labelled;
					}
				}
				break;
			case JCTree.DOLOOP:
			case JCTree.WHILELOOP:
			case JCTree.FORLOOP:
			case JCTree.FOREACHLOOP:
				if (label == null)
					return env1.tree;
				break;
			case JCTree.SWITCH:
				if (label == null && tag == JCTree.BREAK)
					return env1.tree;
				break;
			case JCTree.METHODDEF:
			case JCTree.CLASSDEF:
				break LOOP;
			default:
			}
			env1 = env1.next;
		}
		if (label != null)
			log.error(pos, "undef.label", label);
		else if (tag == JCTree.CONTINUE)
			log.error(pos, "cont.outside.loop");
		else
			log.error(pos, "break.outside.switch.loop");
		return null;
	}

	public void visitReturn(JCReturn tree) {
		// Check that there is an enclosing method which is
		// nested within than the enclosing class.
		if (env.enclMethod == null
				|| env.enclMethod.sym.owner != env.enclClass.sym) {
			log.error(tree.pos(), "ret.outside.meth");

		} else {
			// Attribute return expression, if it exists, and check that
			// it conforms to result type of enclosing method.
			Symbol m = env.enclMethod.sym;
			if (m.type.getReturnType().tag == VOID) {
				if (tree.expr != null)
					log.error(tree.expr.pos(),
							"cant.ret.val.from.meth.decl.void");
			} else if (tree.expr == null) {
				log.error(tree.pos(), "missing.ret.val");
			} else {
				attribExpr(tree.expr, env, m.type.getReturnType());
			}
		}
		result = null;
	}

	public void visitThrow(JCThrow tree) {
		attribExpr(tree.expr, env, syms.throwableType);
		result = null;
	}

	public void visitAssert(JCAssert tree) {
		attribExpr(tree.cond, env, syms.booleanType);
		if (tree.detail != null) {
			chk.checkNonVoid(tree.detail.pos(), attribExpr(tree.detail, env));
		}
		result = null;
	}

	/**
	 * Visitor method for method invocations. NOTE: The method part of an
	 * application will have in its type field the return type of the method,
	 * not the method's type itself!
	 */
	public void visitApply(JCMethodInvocation tree) {
		// The local environment of a method application is
		// a new environment nested in the current one.
		Env<AttrContext> localEnv = env.dup(tree, env.info.dup());

		// The types of the actual method arguments.
		List<Type> argtypes;

		// The types of the actual method type arguments.
		List<Type> typeargtypes = null;

		Name methName = TreeInfo.name(tree.meth);

		boolean isConstructorCall = methName == names._this
				|| methName == names._super;

		if (isConstructorCall) {
			// We are seeing a ...this(...) or ...super(...) call.
			// Check that this is the first statement in a constructor.
			if (checkFirstConstructorStat(tree, env)) {

				// Record the fact
				// that this is a constructor call (using isSelfCall).
				localEnv.info.isSelfCall = true;

				// Attribute arguments, yielding list of argument types.
				argtypes = attribArgs(tree.args, localEnv);
				typeargtypes = attribTypes(tree.typeargs, localEnv);

				// Variable `site' points to the class in which the called
				// constructor is defined.
				Type site = env.enclClass.sym.type;
				if (methName == names._super) {
					if (site == syms.objectType) {
						log.error(tree.meth.pos(), "no.superclass", site);
						site = syms.errType;
					} else {
						site = types.supertype(site);
					}
				}

				if (site.tag == CLASS) {
					if (site.getEnclosingType().tag == CLASS) {
						// we are calling a nested class

						if (tree.meth.getTag() == JCTree.SELECT) {
							JCTree qualifier = ((JCFieldAccess) tree.meth).selected;

							// We are seeing a prefixed call, of the form
							// <expr>.super(...).
							// Check that the prefix expression conforms
							// to the outer instance type of the class.
							chk.checkRefType(
									qualifier.pos(),
									attribExpr(qualifier, localEnv,
											site.getEnclosingType()));
						} else if (methName == names._super) {
							// qualifier omitted; check for existence
							// of an appropriate implicit qualifier.
							rs.resolveImplicitThis(tree.meth.pos(), localEnv,
									site);
						}
					} else if (tree.meth.getTag() == JCTree.SELECT) {
						log.error(tree.meth.pos(), "illegal.qual.not.icls",
								site.tsym);
					}

					// if we're calling a java.lang.Enum constructor,
					// prefix the implicit String and int parameters
					if (site.tsym == syms.enumSym && allowEnums)
						argtypes = argtypes.prepend(syms.intType).prepend(
								syms.stringType);

					// Resolve the called constructor under the assumption
					// that we are referring to a superclass instance of the
					// current instance (JLS ???).
					boolean selectSuperPrev = localEnv.info.selectSuper;
					localEnv.info.selectSuper = true;
					localEnv.info.varArgs = false;
					Symbol sym = rs.resolveConstructor(tree.meth.pos(),
							localEnv, site, argtypes, typeargtypes);
					localEnv.info.selectSuper = selectSuperPrev;

					// Set method symbol to resolved constructor...
					TreeInfo.setSymbol(tree.meth, sym);

					// ...and check that it is legal in the current context.
					// (this will also set the tree's type)
					Type mpt = newMethTemplate(argtypes, typeargtypes);
					checkId(tree.meth, site, sym, localEnv, MTH, mpt,
							tree.varargsElement != null);
				}
				// Otherwise, `site' is an error type and we do nothing
			}
			result = tree.type = syms.voidType;
		} else {
			// Otherwise, we are seeing a regular method call.
			// Attribute the arguments, yielding list of argument types, ...
			argtypes = attribArgs(tree.args, localEnv);
			typeargtypes = attribTypes(tree.typeargs, localEnv);

			// ... and attribute the method using as a prototype a methodtype
			// whose formal argument types is exactly the list of actual
			// arguments (this will also set the method symbol).
			Type mpt = newMethTemplate(argtypes, typeargtypes);
			localEnv.info.varArgs = false;
			Type mtype = attribExpr(tree.meth, localEnv, mpt);
			if (localEnv.info.varArgs)
				assert mtype.isErroneous() || tree.varargsElement != null;

			// Compute the result type.
			Type restype = mtype.getReturnType();

			if (restype.tag == WILDCARD) {
				restype = types.upperBound(restype);
			}

			// as a special case, array.clone() has a result that is
			// the same as static type of the array being cloned
			if (tree.meth.getTag() == JCTree.SELECT && allowCovariantReturns
					&& methName == names.clone
					&& types.isArray(((JCFieldAccess) tree.meth).selected.type))
				restype = ((JCFieldAccess) tree.meth).selected.type;

			// as a special case, x.getClass() has type Class<? extends |X|>
			if (allowGenerics && methName == names.getClass
					&& tree.args.isEmpty()) {
				Type qualifier = (tree.meth.getTag() == JCTree.SELECT) ? ((JCFieldAccess) tree.meth).selected.type
						: env.enclClass.sym.type;
				restype = new ClassType(restype.getEnclosingType(),
						List.<Type> of(new WildcardType(types
								.erasure(qualifier), BoundKind.EXTENDS,
								syms.boundClass)), restype.tsym);
			}

			// Check that value of resulting type is admissible in the
			// current context. Also, capture the return type
			result = check(tree, capture(restype), VAL, pkind, pt);
		}
		chk.validate(tree.typeargs);
	}

	// where
	/**
	 * Check that given application node appears as first statement in a
	 * constructor call.
	 * 
	 * @param tree
	 *            The application node
	 * @param env
	 *            The environment current at the application.
	 */
	boolean checkFirstConstructorStat(JCMethodInvocation tree,
			Env<AttrContext> env) {
		JCMethodDecl enclMethod = env.enclMethod;
		if (enclMethod != null && enclMethod.name == names.init) {
			JCBlock body = enclMethod.body;
			if (body.stats.head.getTag() == JCTree.EXEC
					&& ((JCExpressionStatement) body.stats.head).expr == tree)
				return true;
		}
		log.error(tree.pos(), "call.must.be.first.stmt.in.ctor",
				TreeInfo.name(tree.meth));
		return false;
	}

	/**
	 * Obtain a method type with given argument types.
	 */
	Type newMethTemplate(List<Type> argtypes, List<Type> typeargtypes) {
		MethodType mt = new MethodType(argtypes, null, null, syms.methodClass);
		return (typeargtypes == null) ? mt
				: (Type) new ForAll(typeargtypes, mt);
	}

	public void visitNewClass(JCNewClass tree) {
		Type owntype = syms.errType;

		// The local environment of a class creation is
		// a new environment nested in the current one.
		Env<AttrContext> localEnv = env.dup(tree, env.info.dup());

		// The anonymous inner class definition of the new expression,
		// if one is defined by it.
		JCClassDecl cdef = tree.def;

		// If enclosing class is given, attribute it, and
		// complete class name to be fully qualified
		JCExpression clazz = tree.clazz; // Class field following new
		JCExpression clazzid = // Identifier in class field
		(clazz.getTag() == JCTree.TYPEAPPLY) ? ((JCTypeApply) clazz).clazz
				: clazz;

		JCExpression clazzid1 = clazzid; // The same in fully qualified form

		if (tree.encl != null) {
			// We are seeing a qualified new, of the form
			// <expr>.new C <...> (...) ...
			// In this case, we let clazz stand for the name of the
			// allocated class C prefixed with the type of the qualifier
			// expression, so that we can
			// resolve it with standard techniques later. I.e., if
			// <expr> has type T, then <expr>.new C <...> (...)
			// yields a clazz T.C.
			Type encltype = chk.checkRefType(tree.encl.pos(),
					attribExpr(tree.encl, env));
			clazzid1 = make.at(clazz.pos).Select(make.Type(encltype),
					((JCIdent) clazzid).name);
			if (clazz.getTag() == JCTree.TYPEAPPLY)
				clazz = make.at(tree.pos).TypeApply(clazzid1,
						((JCTypeApply) clazz).arguments);
			else
				clazz = clazzid1;
			// System.out.println(clazz + " generated.");//DEBUG
		}

		// Attribute clazz expression and store
		// symbol + type back into the attributed tree.
		Type clazztype = chk.checkClassType(tree.clazz.pos(),
				attribType(clazz, env), true);
		chk.validate(clazz);
		if (tree.encl != null) {
			// We have to work in this case to store
			// symbol + type back into the attributed tree.
			tree.clazz.type = clazztype;
			TreeInfo.setSymbol(clazzid, TreeInfo.symbol(clazzid1));
			clazzid.type = ((JCIdent) clazzid).sym.type;
			if (!clazztype.isErroneous()) {
				if (cdef != null && clazztype.tsym.isInterface()) {
					log.error(tree.encl.pos(),
							"anon.class.impl.intf.no.qual.for.new");
				} else if (clazztype.tsym.isStatic()) {
					log.error(tree.encl.pos(), "qualified.new.of.static.class",
							clazztype.tsym);
				}
			}
		} else if (!clazztype.tsym.isInterface()
				&& clazztype.getEnclosingType().tag == CLASS) {
			// Check for the existence of an apropos outer instance
			rs.resolveImplicitThis(tree.pos(), env, clazztype);
		}

		// Attribute constructor arguments.
		List<Type> argtypes = attribArgs(tree.args, localEnv);
		List<Type> typeargtypes = attribTypes(tree.typeargs, localEnv);

		// If we have made no mistakes in the class type...
		if (clazztype.tag == CLASS) {
			// Enums may not be instantiated except implicitly
			if (allowEnums
					&& (clazztype.tsym.flags_field & Flags.ENUM) != 0
					&& (env.tree.getTag() != JCTree.VARDEF
							|| (((JCVariableDecl) env.tree).mods.flags & Flags.ENUM) == 0 || ((JCVariableDecl) env.tree).init != tree))
				log.error(tree.pos(), "enum.cant.be.instantiated");
			// Check that class is not abstract
			if (cdef == null
					&& (clazztype.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
				log.error(tree.pos(), "abstract.cant.be.instantiated",
						clazztype.tsym);
			} else if (cdef != null && clazztype.tsym.isInterface()) {
				// Check that no constructor arguments are given to
				// anonymous classes implementing an interface
				if (!argtypes.isEmpty())
					log.error(tree.args.head.pos(),
							"anon.class.impl.intf.no.args");

				if (!typeargtypes.isEmpty())
					log.error(tree.typeargs.head.pos(),
							"anon.class.impl.intf.no.typeargs");

				// Error recovery: pretend no arguments were supplied.
				argtypes = List.nil();
				typeargtypes = List.nil();
			}

			// Resolve the called constructor under the assumption
			// that we are referring to a superclass instance of the
			// current instance (JLS ???).
			else {
				localEnv.info.selectSuper = cdef != null;
				localEnv.info.varArgs = false;
				tree.constructor = rs.resolveConstructor(tree.pos(), localEnv,
						clazztype, argtypes, typeargtypes);
				Type ctorType = checkMethod(clazztype, tree.constructor,
						localEnv, tree.args, argtypes, typeargtypes,
						localEnv.info.varArgs);
				if (localEnv.info.varArgs)
					assert ctorType.isErroneous()
							|| tree.varargsElement != null;
			}

			if (cdef != null) {
				// We are seeing an anonymous class instance creation.
				// In this case, the class instance creation
				// expression
				//
				// E.new <typeargs1>C<typargs2>(args) { ... }
				//
				// is represented internally as
				//
				// E . new <typeargs1>C<typargs2>(args) ( class <empty-name> {
				// ... } ) .
				//
				// This expression is then *transformed* as follows:
				//
				// (1) add a STATIC flag to the class definition
				// if the current environment is static
				// (2) add an extends or implements clause
				// (3) add a constructor.
				//
				// For instance, if C is a class, and ET is the type of E,
				// the expression
				//
				// E.new <typeargs1>C<typargs2>(args) { ... }
				//
				// is translated to (where X is a fresh name and typarams is the
				// parameter list of the super constructor):
				//
				// new <typeargs1>X(<*nullchk*>E, args) where
				// X extends C<typargs2> {
				// <typarams> X(ET e, args) {
				// e.<typeargs1>super(args)
				// }
				// ...
				// }
				if (Resolve.isStatic(env))
					cdef.mods.flags |= STATIC;

				if (clazztype.tsym.isInterface()) {
					cdef.implementing = List.of(clazz);
				} else {
					cdef.extending = clazz;
				}

				attribStat(cdef, localEnv);

				// If an outer instance is given,
				// prefix it to the constructor arguments
				// and delete it from the new expression
				if (tree.encl != null && !clazztype.tsym.isInterface()) {
					tree.args = tree.args.prepend(makeNullCheck(tree.encl));
					argtypes = argtypes.prepend(tree.encl.type);
					tree.encl = null;
				}

				// Reassign clazztype and recompute constructor.
				clazztype = cdef.sym.type;
				Symbol sym = rs.resolveConstructor(tree.pos(), localEnv,
						clazztype, argtypes, typeargtypes, true,
						tree.varargsElement != null);
				assert sym.kind < AMBIGUOUS
						|| tree.constructor.type.isErroneous();
				tree.constructor = sym;
			}

			if (tree.constructor != null && tree.constructor.kind == MTH)
				owntype = clazztype;
		}
		result = check(tree, owntype, VAL, pkind, pt);
		chk.validate(tree.typeargs);
	}

	/**
	 * Make an attributed null check tree.
	 */
	public JCExpression makeNullCheck(JCExpression arg) {
		// optimization: X.this is never null; skip null check
		Name name = TreeInfo.name(arg);
		if (name == names._this || name == names._super)
			return arg;

		int optag = JCTree.NULLCHK;
		JCUnary tree = make.at(arg.pos).Unary(optag, arg);
		tree.operator = syms.nullcheck;
		tree.type = arg.type;
		return tree;
	}

	public void visitNewArray(JCNewArray tree) {
		Type owntype = syms.errType;
		Type elemtype;
		if (tree.elemtype != null) {
			elemtype = attribType(tree.elemtype, env);
			chk.validate(tree.elemtype);
			owntype = elemtype;
			for (List<JCExpression> l = tree.dims; l.nonEmpty(); l = l.tail) {
				attribExpr(l.head, env, syms.intType);
				owntype = new ArrayType(owntype, syms.arrayClass);
			}
		} else {
			// we are seeing an untyped aggregate { ... }
			// this is allowed only if the prototype is an array
			if (pt.tag == ARRAY) {
				elemtype = types.elemtype(pt);
			} else {
				if (pt.tag != ERROR) {
					log.error(tree.pos(), "illegal.initializer.for.type", pt);
				}
				elemtype = syms.errType;
			}
		}
		if (tree.elems != null) {
			attribExprs(tree.elems, env, elemtype);
			owntype = new ArrayType(elemtype, syms.arrayClass);
		}
		if (!types.isReifiable(elemtype))
			log.error(tree.pos(), "generic.array.creation");
		result = check(tree, owntype, VAL, pkind, pt);
	}

	public void visitParens(JCParens tree) {
		Type owntype = attribTree(tree.expr, env, pkind, pt);
		result = check(tree, owntype, pkind, pkind, pt);
		Symbol sym = TreeInfo.symbol(tree);
		if (sym != null && (sym.kind & (TYP | PCK)) != 0)
			log.error(tree.pos(), "illegal.start.of.type");
	}

	public void visitAssign(JCAssign tree) {
		Type owntype = attribTree(tree.lhs, env.dup(tree), VAR, Type.noType);
		Type capturedType = capture(owntype);
		attribExpr(tree.rhs, env, owntype);
		result = check(tree, capturedType, VAL, pkind, pt);
	}

	public void visitAssignop(JCAssignOp tree) {
		// Attribute arguments.
		Type owntype = attribTree(tree.lhs, env, VAR, Type.noType);
		Type operand = attribExpr(tree.rhs, env);
		// Find operator.
		Symbol operator = tree.operator = rs.resolveBinaryOperator(tree.pos(),
				tree.getTag() - JCTree.ASGOffset, env, owntype, operand);

		if (operator.kind == MTH) {
			chk.checkOperator(tree.pos(), (OperatorSymbol) operator,
					tree.getTag() - JCTree.ASGOffset, owntype, operand);
			if (types
					.isSameType(operator.type.getReturnType(), syms.stringType)) {
				// String assignment; make sure the lhs is a string
				chk.checkType(tree.lhs.pos(), owntype, syms.stringType);
			} else {
				chk.checkDivZero(tree.rhs.pos(), operator, operand);
				chk.checkCastable(tree.rhs.pos(),
						operator.type.getReturnType(), owntype);
			}
		}
		result = check(tree, owntype, VAL, pkind, pt);
	}

	public void visitUnary(JCUnary tree) {
		// Attribute arguments.
		Type argtype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC) ? attribTree(
				tree.arg, env, VAR, Type.noType) : chk.checkNonVoid(
				tree.arg.pos(), attribExpr(tree.arg, env));

		// Find operator.
		Symbol operator = tree.operator = rs.resolveUnaryOperator(tree.pos(),
				tree.getTag(), env, argtype);

		Type owntype = syms.errType;
		if (operator.kind == MTH) {
			owntype = (JCTree.PREINC <= tree.getTag() && tree.getTag() <= JCTree.POSTDEC) ? tree.arg.type
					: operator.type.getReturnType();
			int opc = ((OperatorSymbol) operator).opcode;

			// If the argument is constant, fold it.
			if (argtype.constValue() != null) {
				Type ctype = cfolder.fold1(opc, argtype);
				if (ctype != null) {
					owntype = cfolder.coerce(ctype, owntype);

					// Remove constant types from arguments to
					// conserve space. The parser will fold concatenations
					// of string literals; the code here also
					// gets rid of intermediate results when some of the
					// operands are constant identifiers.
					if (tree.arg.type.tsym == syms.stringType.tsym) {
						tree.arg.type = syms.stringType;
					}
				}
			}
		}
		result = check(tree, owntype, VAL, pkind, pt);
	}

	public void visitBinary(JCBinary tree) {
		// Attribute arguments.
		Type left = chk.checkNonVoid(tree.lhs.pos(), attribExpr(tree.lhs, env));
		Type right = chk
				.checkNonVoid(tree.lhs.pos(), attribExpr(tree.rhs, env));

		// Find operator.
		Symbol operator = tree.operator = rs.resolveBinaryOperator(tree.pos(),
				tree.getTag(), env, left, right);

		Type owntype = syms.errType;
		if (operator.kind == MTH) {
			owntype = operator.type.getReturnType();
			int opc = chk.checkOperator(tree.lhs.pos(),
					(OperatorSymbol) operator, tree.getTag(), left, right);

			// If both arguments are constants, fold them.
			if (left.constValue() != null && right.constValue() != null) {
				Type ctype = cfolder.fold2(opc, left, right);
				if (ctype != null) {
					owntype = cfolder.coerce(ctype, owntype);

					// Remove constant types from arguments to
					// conserve space. The parser will fold concatenations
					// of string literals; the code here also
					// gets rid of intermediate results when some of the
					// operands are constant identifiers.
					if (tree.lhs.type.tsym == syms.stringType.tsym) {
						tree.lhs.type = syms.stringType;
					}
					if (tree.rhs.type.tsym == syms.stringType.tsym) {
						tree.rhs.type = syms.stringType;
					}
				}
			}

			// Check that argument types of a reference ==, != are
			// castable to each other, (JLS???).
			if ((opc == ByteCodes.if_acmpeq || opc == ByteCodes.if_acmpne)) {
				if (!types.isCastable(left, right, new Warner(tree.pos()))) {
					log.error(tree.pos(), "incomparable.types", left, right);
				}
			}

			chk.checkDivZero(tree.rhs.pos(), operator, right);
		}
		result = check(tree, owntype, VAL, pkind, pt);
	}

	public void visitTypeCast(JCTypeCast tree) {
		Type clazztype = attribType(tree.clazz, env);
		Type exprtype = attribExpr(tree.expr, env, Infer.anyPoly);
		Type owntype = chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
		if (exprtype.constValue() != null)
			owntype = cfolder.coerce(exprtype, owntype);
		result = check(tree, capture(owntype), VAL, pkind, pt);
	}

	public void visitTypeTest(JCInstanceOf tree) {
		Type exprtype = chk.checkNullOrRefType(tree.expr.pos(),
				attribExpr(tree.expr, env));
		Type clazztype = chk.checkReifiableReferenceType(tree.clazz.pos(),
				attribType(tree.clazz, env));
		chk.checkCastable(tree.expr.pos(), exprtype, clazztype);
		result = check(tree, syms.booleanType, VAL, pkind, pt);
	}

	public void visitIndexed(JCArrayAccess tree) {
		Type owntype = syms.errType;
		Type atype = attribExpr(tree.indexed, env);
		attribExpr(tree.index, env, syms.intType);
		if (types.isArray(atype))
			owntype = types.elemtype(atype);
		else if (atype.tag != ERROR)
			log.error(tree.pos(), "array.req.but.found", atype);
		if ((pkind & VAR) == 0)
			owntype = capture(owntype);
		result = check(tree, owntype, VAR, pkind, pt);
	}

	public void visitIdent(JCIdent tree) {
		Symbol sym;
		boolean varArgs = false;

		// Find symbol
		if (pt.tag == METHOD || pt.tag == FORALL) {
			// If we are looking for a method, the prototype `pt' will be a
			// method type with the type of the call's arguments as parameters.
			env.info.varArgs = false;
			sym = rs.resolveMethod(tree.pos(), env, tree.name,
					pt.getParameterTypes(), pt.getTypeArguments());
			varArgs = env.info.varArgs;
		} else if (tree.sym != null && tree.sym.kind != VAR) {
			sym = tree.sym;
		} else {
			sym = rs.resolveIdent(tree.pos(), env, tree.name, pkind);
		}
		tree.sym = sym;

		// (1) Also find the environment current for the class where
		// sym is defined (`symEnv').
		// Only for pre-tiger versions (1.4 and earlier):
		// (2) Also determine whether we access symbol out of an anonymous
		// class in a this or super call. This is illegal for instance
		// members since such classes don't carry a this$n link.
		// (`noOuterThisPath').
		Env<AttrContext> symEnv = env;
		boolean noOuterThisPath = false;
		if (env.enclClass.sym.owner.kind != PCK
				&& // we are in an inner class
				(sym.kind & (VAR | MTH | TYP)) != 0 && sym.owner.kind == TYP
				&& tree.name != names._this && tree.name != names._super) {

			// Find environment in which identifier is defined.
			while (symEnv.outer != null
					&& !sym.isMemberOf(symEnv.enclClass.sym, types)) {
				if ((symEnv.enclClass.sym.flags() & NOOUTERTHIS) != 0)
					noOuterThisPath = !allowAnonOuterThis;
				symEnv = symEnv.outer;
			}
		}

		// If symbol is a variable, ...
		if (sym.kind == VAR) {
			VarSymbol v = (VarSymbol) sym;

			// ..., evaluate its initializer, if it has one, and check for
			// illegal forward reference.
			checkInit(tree, env, v, false);

			// If symbol is a local variable accessed from an embedded
			// inner class check that it is final.
			if (v.owner.kind == MTH && v.owner != env.info.scope.owner
					&& (v.flags_field & FINAL) == 0) {
				log.error(tree.pos(),
						"local.var.accessed.from.icls.needs.final", v);
			}

			// If we are expecting a variable (as opposed to a value), check
			// that the variable is assignable in the current environment.
			if (pkind == VAR)
				checkAssignable(tree.pos(), v, null, env);
		}

		// In a constructor body,
		// if symbol is a field or instance method, check that it is
		// not accessed before the supertype constructor is called.
		if ((symEnv.info.isSelfCall || noOuterThisPath)
				&& (sym.kind & (VAR | MTH)) != 0 && sym.owner.kind == TYP
				&& (sym.flags() & STATIC) == 0) {
			chk.earlyRefError(tree.pos(),
					sym.kind == VAR ? sym : thisSym(tree.pos(), env));
		}
		Env<AttrContext> env1 = env;
		if (sym.kind != ERR && sym.kind != TYP && sym.owner != null
				&& sym.owner != env1.enclClass.sym) {
			// If the found symbol is inaccessible, then it is
			// accessed through an enclosing instance. Locate this
			// enclosing instance:
			while (env1.outer != null
					&& !rs.isAccessible(env, env1.enclClass.sym.type, sym))
				env1 = env1.outer;
		}
		result = checkId(tree, env1.enclClass.sym.type, sym, env, pkind, pt,
				varArgs);
	}

	public void visitSelect(JCFieldAccess tree) {
		// Determine the expected kind of the qualifier expression.
		int skind = 0;
		if (tree.name == names._this || tree.name == names._super
				|| tree.name == names._class) {
			skind = TYP;
		} else {
			if ((pkind & PCK) != 0)
				skind = skind | PCK;
			if ((pkind & TYP) != 0)
				skind = skind | TYP | PCK;
			if ((pkind & (VAL | MTH)) != 0)
				skind = skind | VAL | TYP;
		}

		// Attribute the qualifier expression, and determine its symbol (if
		// any).
		Type site = attribTree(tree.selected, env, skind, Infer.anyPoly);
		if ((pkind & (PCK | TYP)) == 0)
			site = capture(site); // Capture field access

		// don't allow T.class T[].class, etc
		if (skind == TYP) {
			Type elt = site;
			while (elt.tag == ARRAY)
				elt = ((ArrayType) elt).elemtype;
			if (elt.tag == TYPEVAR) {
				log.error(tree.pos(), "type.var.cant.be.deref");
				result = syms.errType;
				return;
			}
		}

		// If qualifier symbol is a type or `super', assert `selectSuper'
		// for the selection. This is relevant for determining whether
		// protected symbols are accessible.
		Symbol sitesym = TreeInfo.symbol(tree.selected);
		boolean selectSuperPrev = env.info.selectSuper;
		env.info.selectSuper = sitesym != null && sitesym.name == names._super;

		// If selected expression is polymorphic, strip
		// type parameters and remember in env.info.tvars, so that
		// they can be added later (in Attr.checkId and
		// Infer.instantiateMethod).
		if (tree.selected.type.tag == FORALL) {
			ForAll pstype = (ForAll) tree.selected.type;
			env.info.tvars = pstype.tvars;
			site = tree.selected.type = pstype.qtype;
		}

		// Determine the symbol represented by the selection.
		env.info.varArgs = false;
		Symbol sym = selectSym(tree, site, env, pt, pkind);
		if (sym.exists() && !isType(sym) && (pkind & (PCK | TYP)) != 0) {
			site = capture(site);
			sym = selectSym(tree, site, env, pt, pkind);
		}
		boolean varArgs = env.info.varArgs;
		tree.sym = sym;

		if (site.tag == TYPEVAR && !isType(sym) && sym.kind != ERR)
			site = capture(site.getUpperBound());

		// If that symbol is a variable, ...
		if (sym.kind == VAR) {
			VarSymbol v = (VarSymbol) sym;

			// ..., evaluate its initializer, if it has one, and check for
			// illegal forward reference.
			checkInit(tree, env, v, true);

			// If we are expecting a variable (as opposed to a value), check
			// that the variable is assignable in the current environment.
			if (pkind == VAR)
				checkAssignable(tree.pos(), v, tree.selected, env);
		}

		// Disallow selecting a type from an expression
		if (isType(sym)
				&& (sitesym == null || (sitesym.kind & (TYP | PCK)) == 0)) {
			tree.type = check(tree.selected, pt, sitesym == null ? VAL
					: sitesym.kind, TYP | PCK, pt);
		}

		if (isType(sitesym)) {
			if (sym.name == names._this) {
				// If `C' is the currently compiled class, check that
				// C.this' does not appear in a call to a super(...)
				if (env.info.isSelfCall && site.tsym == env.enclClass.sym) {
					chk.earlyRefError(tree.pos(), sym);
				}
			} else {
				// Check if type-qualified fields or methods are static (JLS)
				if ((sym.flags() & STATIC) == 0 && sym.name != names._super
						&& (sym.kind == VAR || sym.kind == MTH)) {
					rs.access(rs.new StaticError(sym), tree.pos(), site,
							sym.name, true);
				}
			}
		}

		// If we are selecting an instance member via a `super', ...
		if (env.info.selectSuper && (sym.flags() & STATIC) == 0) {

			// Check that super-qualified symbols are not abstract (JLS)
			rs.checkNonAbstract(tree.pos(), sym);

			if (site.isRaw()) {
				// Determine argument types for site.
				Type site1 = types.asSuper(env.enclClass.sym.type, site.tsym);
				if (site1 != null)
					site = site1;
			}
		}

		env.info.selectSuper = selectSuperPrev;
		result = checkId(tree, site, sym, env, pkind, pt, varArgs);
		env.info.tvars = List.nil();
	}

	// where
	/**
	 * Determine symbol referenced by a Select expression,
	 * 
	 * @param tree
	 *            The select tree.
	 * @param site
	 *            The type of the selected expression,
	 * @param env
	 *            The current environment.
	 * @param pt
	 *            The current prototype.
	 * @param pkind
	 *            The expected kind(s) of the Select expression.
	 */
	private Symbol selectSym(JCFieldAccess tree, Type site,
			Env<AttrContext> env, Type pt, int pkind) {
		DiagnosticPosition pos = tree.pos();
		Name name = tree.name;

		switch (site.tag) {
		case PACKAGE:
			return rs.access(
					rs.findIdentInPackage(env, site.tsym, name, pkind), pos,
					site, name, true);
		case ARRAY:
		case CLASS:
			if (pt.tag == METHOD || pt.tag == FORALL) {
				return rs.resolveQualifiedMethod(pos, env, site, name,
						pt.getParameterTypes(), pt.getTypeArguments());
			} else if (name == names._this || name == names._super) {
				return rs.resolveSelf(pos, env, site.tsym, name);
			} else if (name == names._class) {
				// In this case, we have already made sure in
				// visitSelect that qualifier expression is a type.
				Type t = syms.classType;
				List<Type> typeargs = allowGenerics ? List.of(types
						.erasure(site)) : List.<Type> nil();
				t = new ClassType(t.getEnclosingType(), typeargs, t.tsym);
				return new VarSymbol(STATIC | PUBLIC | FINAL, names._class, t,
						site.tsym);
			} else {
				// We are seeing a plain identifier as selector.
				Symbol sym = rs.findIdentInType(env, site, name, pkind);
				if ((pkind & ERRONEOUS) == 0)
					sym = rs.access(sym, pos, site, name, true);
				return sym;
			}
		case WILDCARD:
			throw new AssertionError(tree);
		case TYPEVAR:
			// Normally, site.getUpperBound() shouldn't be null.
			// It should only happen during memberEnter/attribBase
			// when determining the super type which *must* be
			// done before attributing the type variables. In
			// other words, we are seeing this illegal program:
			// class B<T> extends A<T.foo> {}
			Symbol sym = (site.getUpperBound() != null) ? selectSym(tree,
					capture(site.getUpperBound()), env, pt, pkind) : null;
			if (sym == null || isType(sym)) {
				log.error(pos, "type.var.cant.be.deref");
				return syms.errSymbol;
			} else {
				return sym;
			}
		case ERROR:
			// preserve identifier names through errors
			return new ErrorType(name, site.tsym).tsym;
		default:
			// The qualifier expression is of a primitive type -- only
			// .class is allowed for these.
			if (name == names._class) {
				// In this case, we have already made sure in Select that
				// qualifier expression is a type.
				Type t = syms.classType;
				Type arg = types.boxedClass(site).type;
				t = new ClassType(t.getEnclosingType(), List.of(arg), t.tsym);
				return new VarSymbol(STATIC | PUBLIC | FINAL, names._class, t,
						site.tsym);
			} else {
				log.error(pos, "cant.deref", site);
				return syms.errSymbol;
			}
		}
	}

	/**
	 * Determine type of identifier or select expression and check that (1) the
	 * referenced symbol is not deprecated (2) the symbol's type is safe (@see
	 * checkSafe) (3) if symbol is a variable, check that its type and kind are
	 * compatible with the prototype and protokind. (4) if symbol is an instance
	 * field of a raw type, which is being assigned to, issue an unchecked
	 * warning if its type changes under erasure. (5) if symbol is an instance
	 * method of a raw type, issue an unchecked warning if its argument types
	 * change under erasure. If checks succeed: If symbol is a constant, return
	 * its constant type else if symbol is a method, return its result type
	 * otherwise return its type. Otherwise return errType.
	 * 
	 * @param tree
	 *            The syntax tree representing the identifier
	 * @param site
	 *            If this is a select, the type of the selected expression,
	 *            otherwise the type of the current class.
	 * @param sym
	 *            The symbol representing the identifier.
	 * @param env
	 *            The current environment.
	 * @param pkind
	 *            The set of expected kinds.
	 * @param pt
	 *            The expected type.
	 */
	Type checkId(JCTree tree, Type site, Symbol sym, Env<AttrContext> env,
			int pkind, Type pt, boolean useVarargs) {
		if (pt.isErroneous())
			return syms.errType;
		Type owntype; // The computed type of this identifier occurrence.
		switch (sym.kind) {
		case TYP:
			// For types, the computed type equals the symbol's type,
			// except for two situations:
			owntype = sym.type;
			if (owntype.tag == CLASS) {
				Type ownOuter = owntype.getEnclosingType();

				// (a) If the symbol's type is parameterized, erase it
				// because no type parameters were given.
				// We recover generic outer type later in visitTypeApply.
				if (owntype.tsym.type.getTypeArguments().nonEmpty()) {
					owntype = types.erasure(owntype);
				}

				// (b) If the symbol's type is an inner class, then
				// we have to interpret its outer type as a superclass
				// of the site type. Example:
				//
				// class Tree<A> { class Visitor { ... } }
				// class PointTree extends Tree<Point> { ... }
				// ...PointTree.Visitor...
				//
				// Then the type of the last expression above is
				// Tree<Point>.Visitor.
				else if (ownOuter.tag == CLASS && site != ownOuter) {
					Type normOuter = site;
					if (normOuter.tag == CLASS)
						normOuter = types.asEnclosingSuper(site, ownOuter.tsym);
					if (normOuter == null) // perhaps from an import
						normOuter = types.erasure(ownOuter);
					if (normOuter != ownOuter)
						owntype = new ClassType(normOuter, List.<Type> nil(),
								owntype.tsym);
				}
			}
			break;
		case VAR:
			VarSymbol v = (VarSymbol) sym;
			// Test (4): if symbol is an instance field of a raw type,
			// which is being assigned to, issue an unchecked warning if
			// its type changes under erasure.
			if (allowGenerics && pkind == VAR && v.owner.kind == TYP
					&& (v.flags() & STATIC) == 0
					&& (site.tag == CLASS || site.tag == TYPEVAR)) {
				Type s = types.asOuterSuper(site, v.owner);
				if (s != null && s.isRaw()
						&& !types.isSameType(v.type, v.erasure(types))) {
					chk.warnUnchecked(tree.pos(), "unchecked.assign.to.var", v,
							s);
				}
			}
			// The computed type of a variable is the type of the
			// variable symbol, taken as a member of the site type.
			owntype = (sym.owner.kind == TYP && sym.name != names._this && sym.name != names._super) ? types
					.memberType(site, sym) : sym.type;

			if (env.info.tvars.nonEmpty()) {
				Type owntype1 = new ForAll(env.info.tvars, owntype);
				for (List<Type> l = env.info.tvars; l.nonEmpty(); l = l.tail)
					if (!owntype.contains(l.head)) {
						log.error(tree.pos(), "undetermined.type", owntype1);
						owntype1 = syms.errType;
					}
				owntype = owntype1;
			}

			// If the variable is a constant, record constant value in
			// computed type.
			if (v.getConstValue() != null && isStaticReference(tree))
				owntype = owntype.constType(v.getConstValue());

			if (pkind == VAL) {
				owntype = capture(owntype); // capture "names as expressions"
			}
			break;
		case MTH: {
			JCMethodInvocation app = (JCMethodInvocation) env.tree;
			owntype = checkMethod(site, sym, env, app.args,
					pt.getParameterTypes(), pt.getTypeArguments(),
					env.info.varArgs);
			break;
		}
		case PCK:
		case ERR:
			owntype = sym.type;
			break;
		default:
			throw new AssertionError("unexpected kind: " + sym.kind
					+ " in tree " + tree);
		}

		// Test (1): emit a `deprecation' warning if symbol is deprecated.
		// (for constructors, the error was given when the constructor was
		// resolved)
		if (sym.name != names.init
				&& (sym.flags() & DEPRECATED) != 0
				&& (env.info.scope.owner.flags() & DEPRECATED) == 0
				&& sym.outermostClass() != env.info.scope.owner
						.outermostClass())
			chk.warnDeprecated(tree.pos(), sym);

		if ((sym.flags() & PROPRIETARY) != 0)
			log.strictWarning(tree.pos(), "sun.proprietary", sym);

		// Test (3): if symbol is a variable, check that its type and
		// kind are compatible with the prototype and protokind.
		return check(tree, owntype, sym.kind, pkind, pt);
	}

	/**
	 * Check that variable is initialized and evaluate the variable's
	 * initializer, if not yet done. Also check that variable is not referenced
	 * before it is defined.
	 * 
	 * @param tree
	 *            The tree making up the variable reference.
	 * @param env
	 *            The current environment.
	 * @param v
	 *            The variable's symbol.
	 */
	private void checkInit(JCTree tree, Env<AttrContext> env, VarSymbol v,
			boolean onlyWarning) {
		// System.err.println(v + " " + ((v.flags() & STATIC) != 0) + " " +
		// tree.pos + " " + v.pos + " " +
		// Resolve.isStatic(env));//DEBUG

		// A forward reference is diagnosed if the declaration position
		// of the variable is greater than the current tree position
		// and the tree and variable definition occur in the same class
		// definition. Note that writes don't count as references.
		// This check applies only to class and instance
		// variables. Local variables follow different scope rules,
		// and are subject to definite assignment checking.
		if (v.pos > tree.pos
				&& v.owner.kind == TYP
				&& canOwnInitializer(env.info.scope.owner)
				&& v.owner == env.info.scope.owner.enclClass()
				&& ((v.flags() & STATIC) != 0) == Resolve.isStatic(env)
				&& (env.tree.getTag() != JCTree.ASSIGN || TreeInfo
						.skipParens(((JCAssign) env.tree).lhs) != tree)) {

			if (!onlyWarning || isStaticEnumField(v)) {
				log.error(tree.pos(), "illegal.forward.ref");
			} else if (useBeforeDeclarationWarning) {
				log.warning(tree.pos(), "forward.ref", v);
			}
		}

		v.getConstValue(); // ensure initializer is evaluated

		checkEnumInitializer(tree, env, v);
	}

	/**
	 * Check for illegal references to static members of enum. In an enum type,
	 * constructors and initializers may not reference its static members unless
	 * they are constant.
	 * 
	 * @param tree
	 *            The tree making up the variable reference.
	 * @param env
	 *            The current environment.
	 * @param v
	 *            The variable's symbol.
	 * @see JLS 3rd Ed. (8.9 Enums)
	 */
	private void checkEnumInitializer(JCTree tree, Env<AttrContext> env,
			VarSymbol v) {
		// JLS 3rd Ed.:
		//
		// "It is a compile-time error to reference a static field
		// of an enum type that is not a compile-time constant
		// (15.28) from constructors, instance initializer blocks,
		// or instance variable initializer expressions of that
		// type. It is a compile-time error for the constructors,
		// instance initializer blocks, or instance variable
		// initializer expressions of an enum constant e to refer
		// to itself or to an enum constant of the same type that
		// is declared to the right of e."
		if (isStaticEnumField(v)) {
			ClassSymbol enclClass = env.info.scope.owner.enclClass();

			if (enclClass == null || enclClass.owner == null)
				return;

			// See if the enclosing class is the enum (or a
			// subclass thereof) declaring v. If not, this
			// reference is OK.
			if (v.owner != enclClass
					&& !types.isSubtype(enclClass.type, v.owner.type))
				return;

			// If the reference isn't from an initializer, then
			// the reference is OK.
			if (!Resolve.isInitializer(env))
				return;

			log.error(tree.pos(), "illegal.enum.static.ref");
		}
	}

	/**
	 * Is the given symbol a static, non-constant field of an Enum? Note: enum
	 * literals should not be regarded as such
	 */
	private boolean isStaticEnumField(VarSymbol v) {
		return Flags.isEnum(v.owner) && Flags.isStatic(v)
				&& !Flags.isConstant(v) && v.name != names._class;
	}

	/**
	 * Can the given symbol be the owner of code which forms part if class
	 * initialization? This is the case if the symbol is a type or field, or if
	 * the symbol is the synthetic method. owning a block.
	 */
	private boolean canOwnInitializer(Symbol sym) {
		return (sym.kind & (VAR | TYP)) != 0
				|| (sym.kind == MTH && (sym.flags() & BLOCK) != 0);
	}

	Warner noteWarner = new Warner();

	/**
	 * Check that method arguments conform to its instantation.
	 **/
	public Type checkMethod(Type site, Symbol sym, Env<AttrContext> env,
			final List<JCExpression> argtrees, List<Type> argtypes,
			List<Type> typeargtypes, boolean useVarargs) {
		// Test (5): if symbol is an instance method of a raw type, issue
		// an unchecked warning if its argument types change under erasure.
		if (allowGenerics && (sym.flags() & STATIC) == 0
				&& (site.tag == CLASS || site.tag == TYPEVAR)) {
			Type s = types.asOuterSuper(site, sym.owner);
			if (s != null
					&& s.isRaw()
					&& !types.isSameTypes(sym.type.getParameterTypes(), sym
							.erasure(types).getParameterTypes())) {
				chk.warnUnchecked(env.tree.pos(),
						"unchecked.call.mbr.of.raw.type", sym, s);
			}
		}

		// Compute the identifier's instantiated type.
		// For methods, we need to compute the instance type by
		// Resolve.instantiate from the symbol's type as well as
		// any type arguments and value arguments.
		noteWarner.warned = false;
		Type owntype = rs.instantiate(env, site, sym, argtypes, typeargtypes,
				true, useVarargs, noteWarner);
		boolean warned = noteWarner.warned;

		// If this fails, something went wrong; we should not have
		// found the identifier in the first place.
		if (owntype == null) {
			if (!pt.isErroneous())
				log.error(env.tree.pos(), "internal.error.cant.instantiate",
						sym, site, Type.toString(pt.getParameterTypes()));
			owntype = syms.errType;
		} else {
			// System.out.println("call   : " + env.tree);
			// System.out.println("method : " + owntype);
			// System.out.println("actuals: " + argtypes);
			List<Type> formals = owntype.getParameterTypes();
			Type last = useVarargs ? formals.last() : null;
			if (sym.name == names.init && sym.owner == syms.enumSym)
				formals = formals.tail.tail;
			List<JCExpression> args = argtrees;
			while (formals.head != last) {
				JCTree arg = args.head;
				Warner warn = chk.convertWarner(arg.pos(), arg.type,
						formals.head);
				assertConvertible(arg, arg.type, formals.head, warn);
				warned |= warn.warned;
				args = args.tail;
				formals = formals.tail;
			}
			if (useVarargs) {
				Type varArg = types.elemtype(last);
				while (args.tail != null) {
					JCTree arg = args.head;
					Warner warn = chk
							.convertWarner(arg.pos(), arg.type, varArg);
					assertConvertible(arg, arg.type, varArg, warn);
					warned |= warn.warned;
					args = args.tail;
				}
			} else if ((sym.flags() & VARARGS) != 0 && allowVarargs) {
				// non-varargs call to varargs method
				Type varParam = owntype.getParameterTypes().last();
				Type lastArg = argtypes.last();
				if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam))
						&& !types.isSameType(types.erasure(varParam),
								types.erasure(lastArg)))
					log.warning(argtrees.last().pos(),
							"inexact.non-varargs.call",
							types.elemtype(varParam), varParam);
			}

			if (warned && sym.type.tag == FORALL) {
				String typeargs = "";
				if (typeargtypes != null && typeargtypes.nonEmpty()) {
					typeargs = "<" + Type.toString(typeargtypes) + ">";
				}
				chk.warnUnchecked(env.tree.pos(),
						"unchecked.meth.invocation.applied", sym,
						sym.location(), typeargs, Type.toString(argtypes));
				owntype = new MethodType(owntype.getParameterTypes(),
						types.erasure(owntype.getReturnType()),
						owntype.getThrownTypes(), syms.methodClass);
			}
			if (useVarargs) {
				JCTree tree = env.tree;
				Type argtype = owntype.getParameterTypes().last();
				if (!types.isReifiable(argtype))
					chk.warnUnchecked(env.tree.pos(),
							"unchecked.generic.array.creation", argtype);
				Type elemtype = types.elemtype(argtype);
				switch (tree.getTag()) {
				case JCTree.APPLY:
					((JCMethodInvocation) tree).varargsElement = elemtype;
					break;
				case JCTree.NEWCLASS:
					((JCNewClass) tree).varargsElement = elemtype;
					break;
				default:
					throw new AssertionError("" + tree);
				}
			}
		}
		return owntype;
	}

	@SuppressWarnings("unused")
	private void assertConvertible(JCTree tree, Type actual, Type formal,
			Warner warn) {
		if (types.isConvertible(actual, formal, warn))
			return;

		if (formal.isCompound()
				&& types.isSubtype(actual, types.supertype(formal))
				&& types.isSubtypeUnchecked(actual, types.interfaces(formal),
						warn))
			return;

		if (false) {
			// TODO: make assertConvertible work
			chk.typeError(tree.pos(),
					JCDiagnostic.fragment("incompatible.types"), actual, formal);
			throw new AssertionError("Tree: " + tree + " actual:" + actual
					+ " formal: " + formal);
		}
	}

	public void visitLiteral(JCLiteral tree) {
		result = check(tree, litType(tree.typetag).constType(tree.value), VAL,
				pkind, pt);
	}

	// where
	/**
	 * Return the type of a literal with given type tag.
	 */
	Type litType(int tag) {
		return (tag == TypeTags.CLASS) ? syms.stringType : syms.typeOfTag[tag];
	}

	public void visitTypeIdent(JCPrimitiveTypeTree tree) {
		result = check(tree, syms.typeOfTag[tree.typetag], TYP, pkind, pt);
	}

	public void visitTypeArray(JCArrayTypeTree tree) {
		Type etype = attribType(tree.elemtype, env);
		Type type = new ArrayType(etype, syms.arrayClass);
		result = check(tree, type, TYP, pkind, pt);
	}

	/**
	 * Visitor method for parameterized types. Bound checking is left until
	 * later, since types are attributed before supertype structure is
	 * completely known
	 */
	public void visitTypeApply(JCTypeApply tree) {
		Type owntype = syms.errType;

		// Attribute functor part of application and make sure it's a class.
		Type clazztype = chk.checkClassType(tree.clazz.pos(),
				attribType(tree.clazz, env));

		// Attribute type parameters
		List<Type> actuals = attribTypes(tree.arguments, env);

		if (clazztype.tag == CLASS) {
			List<Type> formals = clazztype.tsym.type.getTypeArguments();

			if (actuals.length() == formals.length()) {
				List<Type> a = actuals;
				List<Type> f = formals;
				while (a.nonEmpty()) {
					a.head = a.head.withTypeVar(f.head);
					a = a.tail;
					f = f.tail;
				}
				// Compute the proper generic outer
				Type clazzOuter = clazztype.getEnclosingType();
				if (clazzOuter.tag == CLASS) {
					Type site;
					if (tree.clazz.getTag() == JCTree.IDENT) {
						site = env.enclClass.sym.type;
					} else if (tree.clazz.getTag() == JCTree.SELECT) {
						site = ((JCFieldAccess) tree.clazz).selected.type;
					} else
						throw new AssertionError("" + tree);
					if (clazzOuter.tag == CLASS && site != clazzOuter) {
						if (site.tag == CLASS)
							site = types.asOuterSuper(site, clazzOuter.tsym);
						if (site == null)
							site = types.erasure(clazzOuter);
						clazzOuter = site;
					}
				}
				owntype = new ClassType(clazzOuter, actuals, clazztype.tsym);
			} else {
				if (formals.length() != 0) {
					log.error(tree.pos(), "wrong.number.type.args",
							Integer.toString(formals.length()));
				} else {
					log.error(tree.pos(), "type.doesnt.take.params",
							clazztype.tsym);
				}
				owntype = syms.errType;
			}
		}
		result = check(tree, owntype, TYP, pkind, pt);
	}

	public void visitTypeParameter(JCTypeParameter tree) {
		TypeVar a = (TypeVar) tree.type;
		Set<Type> boundSet = new HashSet<Type>();
		if (a.bound.isErroneous())
			return;
		List<Type> bs = types.getBounds(a);
		if (tree.bounds.nonEmpty()) {
			// accept class or interface or typevar as first bound.
			Type b = checkBase(bs.head, tree.bounds.head, env, false, false,
					false);
			boundSet.add(types.erasure(b));
			if (b.tag == TYPEVAR) {
				// if first bound was a typevar, do not accept further bounds.
				if (tree.bounds.tail.nonEmpty()) {
					log.error(tree.bounds.tail.head.pos(),
							"type.var.may.not.be.followed.by.other.bounds");
					log.unrecoverableError = true;
					tree.bounds = List.of(tree.bounds.head);
				}
			} else {
				// if first bound was a class or interface, accept only
				// interfaces
				// as further bounds.
				for (JCExpression bound : tree.bounds.tail) {
					bs = bs.tail;
					Type i = checkBase(bs.head, bound, env, false, true, false);
					if (i.tag == CLASS)
						chk.checkNotRepeated(bound.pos(), types.erasure(i),
								boundSet);
				}
			}
		}
		bs = types.getBounds(a);

		// in case of multiple bounds ...
		if (bs.length() > 1) {
			// ... the variable's bound is a class type flagged COMPOUND
			// (see comment for TypeVar.bound).
			// In this case, generate a class tree that represents the
			// bound class, ...
			JCTree extending;
			List<JCExpression> implementing;
			if ((bs.head.tsym.flags() & INTERFACE) == 0) {
				extending = tree.bounds.head;
				implementing = tree.bounds.tail;
			} else {
				extending = null;
				implementing = tree.bounds;
			}
			JCClassDecl cd = make.at(tree.pos).ClassDef(
					make.Modifiers(PUBLIC | ABSTRACT), tree.name,
					List.<JCTypeParameter> nil(), extending, implementing,
					List.<JCTree> nil());

			ClassSymbol c = (ClassSymbol) a.getUpperBound().tsym;
			assert (c.flags() & COMPOUND) != 0;
			cd.sym = c;
			c.sourcefile = env.toplevel.sourcefile;

			// ... and attribute the bound class
			c.flags_field |= UNATTRIBUTED;
			Env<AttrContext> cenv = enter.classEnv(cd, env);
			enter.typeEnvs.put(c, cenv);
		}
	}

	public void visitWildcard(JCWildcard tree) {
		// - System.err.println("visitWildcard("+tree+");");//DEBUG
		Type type = (tree.kind.kind == BoundKind.UNBOUND) ? syms.objectType
				: attribType(tree.inner, env);
		result = check(tree,
				new WildcardType(chk.checkRefType(tree.pos(), type),
						tree.kind.kind, syms.boundClass), TYP, pkind, pt);
	}

	public void visitAnnotation(JCAnnotation tree) {
		log.error(tree.pos(), "annotation.not.valid.for.type", pt);
		result = tree.type = syms.errType;
	}

	public void visitErroneous(JCErroneous tree) {
		if (tree.errs != null)
			for (JCTree err : tree.errs)
				attribTree(err, env, ERR, pt);
		result = tree.type = syms.errType;
	}

	/**
	 * Default visitor method for all other trees.
	 */
	public void visitTree(JCTree tree) {
		throw new AssertionError();
	}

	/**
	 * Main method: attribute class definition associated with given class
	 * symbol. reporting completion failures at the given position.
	 * 
	 * @param pos
	 *            The source position at which completion errors are to be
	 *            reported.
	 * @param c
	 *            The class symbol whose definition will be attributed.
	 */
	public void attribClass(DiagnosticPosition pos, ClassSymbol c) {
		try {
			annotate.flush();
			attribClass(c);
		} catch (CompletionFailure ex) {
			chk.completionError(pos, ex);
		}
	}

	/**
	 * Attribute class definition associated with given class symbol.
	 * 
	 * @param c
	 *            The class symbol whose definition will be attributed.
	 */
	void attribClass(ClassSymbol c) throws CompletionFailure {
		if (c.type.tag == ERROR)
			return;

		// Check for cycles in the inheritance graph, which can arise from
		// ill-formed class files.
		chk.checkNonCyclic(null, c.type);

		Type st = types.supertype(c.type);
		if ((c.flags_field & Flags.COMPOUND) == 0) {
			// First, attribute superclass.
			if (st.tag == CLASS)
				attribClass((ClassSymbol) st.tsym);

			// Next attribute owner, if it is a class.
			if (c.owner.kind == TYP && c.owner.type.tag == CLASS)
				attribClass((ClassSymbol) c.owner);
		}

		// The previous operations might have attributed the current class
		// if there was a cycle. So we test first whether the class is still
		// UNATTRIBUTED.
		if ((c.flags_field & UNATTRIBUTED) != 0) {
			c.flags_field &= ~UNATTRIBUTED;

			// Get environment current at the point of class definition.
			Env<AttrContext> env = enter.typeEnvs.get(c);

			// The info.lint field in the envs stored in enter.typeEnvs is
			// deliberately uninitialized,
			// because the annotations were not available at the time the env
			// was created. Therefore,
			// we look up the environment chain for the first enclosing
			// environment for which the
			// lint value is set. Typically, this is the parent env, but might
			// be further if there
			// are any envs created as a result of TypeParameter nodes.
			Env<AttrContext> lintEnv = env;
			while (lintEnv.info.lint == null)
				lintEnv = lintEnv.next;

			// Having found the enclosing lint value, we can initialize the lint
			// value for this class
			env.info.lint = lintEnv.info.lint.augment(c.attributes_field,
					c.flags());

			Lint prevLint = chk.setLint(env.info.lint);
			JavaFileObject prev = log.useSource(c.sourcefile);

			try {
				// java.lang.Enum may not be subclassed by a non-enum
				if (st.tsym == syms.enumSym
						&& ((c.flags_field & (Flags.ENUM | Flags.COMPOUND)) == 0))
					log.error(env.tree.pos(), "enum.no.subclassing");

				// Enums may not be extended by source-level classes
				if (st.tsym != null
						&& ((st.tsym.flags_field & Flags.ENUM) != 0)
						&& ((c.flags_field & Flags.ENUM) == 0)
						&& !target.compilerBootstrap(c)) {
					log.error(env.tree.pos(), "enum.types.not.extensible");
				}
				attribClassBody(env, c);

				chk.checkDeprecatedAnnotation(env.tree.pos(), c);
			} finally {
				log.useSource(prev);
				chk.setLint(prevLint);
			}

		}
	}

	public void visitImport(JCImport tree) {
		// nothing to do
	}

	/** Finish the attribution of a class. */
	private void attribClassBody(Env<AttrContext> env, ClassSymbol c) {
		JCClassDecl tree = (JCClassDecl) env.tree;
		assert c == tree.sym;

		// Validate annotations
		chk.validateAnnotations(tree.mods.annotations, c);

		// Validate type parameters, supertype and interfaces.
		attribBounds(tree.typarams);
		chk.validateTypeParams(tree.typarams);
		chk.validate(tree.extending);
		chk.validate(tree.implementing);

		// If this is a non-abstract class, check that it has no abstract
		// methods or unimplemented methods of an implemented interface.
		if ((c.flags() & (ABSTRACT | INTERFACE)) == 0) {
			if (!relax)
				chk.checkAllDefined(tree.pos(), c);
		}

		if ((c.flags() & ANNOTATION) != 0) {
			if (tree.implementing.nonEmpty())
				log.error(tree.implementing.head.pos(),
						"cant.extend.intf.annotation");
			if (tree.typarams.nonEmpty())
				log.error(tree.typarams.head.pos(),
						"intf.annotation.cant.have.type.params");
		} else {
			// Check that all extended classes and interfaces
			// are compatible (i.e. no two define methods with same arguments
			// yet different return types). (JLS 8.4.6.3)
			chk.checkCompatibleSupertypes(tree.pos(), c.type);
		}

		// Check that class does not import the same parameterized interface
		// with two different argument lists.
		chk.checkClassBounds(tree.pos(), c.type);

		tree.type = c.type;

		boolean assertsEnabled = false;
		assert assertsEnabled = true;
		if (assertsEnabled) {
			for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
				assert env.info.scope.lookup(l.head.name).scope != null;
		}

		// Check that a generic class doesn't extend Throwable
		if (!c.type.allparams().isEmpty()
				&& types.isSubtype(c.type, syms.throwableType))
			log.error(tree.extending.pos(), "generic.throwable");

		// Check that all methods which implement some
		// method conform to the method they implement.
		chk.checkImplementations(tree);

		for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
			// Attribute declaration
			attribStat(l.head, env);
			// Check that declarations in inner classes are not static (JLS
			// 8.1.2)
			// Make an exception for static constants.
			if (c.owner.kind != PCK
					&& ((c.flags() & STATIC) == 0 || c.name == names.empty)
					&& (TreeInfo.flags(l.head) & (STATIC | INTERFACE)) != 0) {
				Symbol sym = null;
				if (l.head.getTag() == JCTree.VARDEF)
					sym = ((JCVariableDecl) l.head).sym;
				if (sym == null || sym.kind != VAR
						|| ((VarSymbol) sym).getConstValue() == null)
					log.error(l.head.pos(), "icls.cant.have.static.decl");
			}
		}

		// Check for cycles among non-initial constructors.
		chk.checkCyclicConstructors(tree);

		// Check for cycles among annotation elements.
		chk.checkNonCyclicElements(tree);

		// Check for proper use of serialVersionUID
		if (env.info.lint.isEnabled(Lint.LintCategory.SERIAL)
				&& isSerializable(c) && (c.flags() & Flags.ENUM) == 0
				&& (c.flags() & ABSTRACT) == 0) {
			checkSerialVersionUID(tree, c);
		}
	}

	// where
	/** check if a class is a subtype of Serializable, if that is available. */
	private boolean isSerializable(ClassSymbol c) {
		try {
			syms.serializableType.complete();
		} catch (CompletionFailure e) {
			return false;
		}
		return types.isSubtype(c.type, syms.serializableType);
	}

	/** Check that an appropriate serialVersionUID member is defined. */
	private void checkSerialVersionUID(JCClassDecl tree, ClassSymbol c) {

		// check for presence of serialVersionUID
		Scope.Entry e = c.members().lookup(names.serialVersionUID);
		while (e.scope != null && e.sym.kind != VAR)
			e = e.next();
		if (e.scope == null) {
			log.warning(tree.pos(), "missing.SVUID", c);
			return;
		}

		// check that it is static final
		VarSymbol svuid = (VarSymbol) e.sym;
		if ((svuid.flags() & (STATIC | FINAL)) != (STATIC | FINAL))
			log.warning(TreeInfo.diagnosticPositionFor(svuid, tree),
					"improper.SVUID", c);

		// check that it is long
		else if (svuid.type.tag != TypeTags.LONG)
			log.warning(TreeInfo.diagnosticPositionFor(svuid, tree),
					"long.SVUID", c);

		// check constant
		else if (svuid.getConstValue() == null)
			log.warning(TreeInfo.diagnosticPositionFor(svuid, tree),
					"constant.SVUID", c);
	}

	private Type capture(Type type) {
		return types.capture(type);
	}
}
